Porth Reservoir

A circular walk through the wildlife reserve around the reservoir lake, past crumbling ruins of Fir Hill Manor and via farmland, a mill and wooded vales that were also once part of the great estate.

Get the app to guide you around the walk

Phone showing walk for purchase
Download the (free) app then use it to purchase this walk.
Phone showing Google navigation to start of walk
The app will direct you via satnav the start of the walk.
Hand holding a phone showing the iWalk Cornwall app
The app leads you around the walk using GPS, removing any worries about getting lost.
Person looking a directions on phone
Each time there is a new direction to follow, the app will beep to remind you, and will warn you if you go off-route.
Phone showing walk map page in the iWalk Cornwall app
A map shows the route, where you are and which way you are facing.
Phone showing walk directions page in the iWalk Cornwall app
Detailed, triple-tested directions are also included.
Phone showing facts section in iWalk Cornwall app
Each walk includes lots of information about the history and nature along the route.
Person look at phone with cliff scenery in background
Once a walk is downloaded, the app doesn't need a phone or wifi signal for the walk.
Phone showing walk stats in the iWalk Cornwall app
The app counts down distance to the next direction and estimates time remaining based on your personal walking speed.
Person repairing footpath sign
We keep the directions continually updated for changes to the paths/landmarks - the price of £1.99 for a walk includes ongoing free updates.
The walk starts along the edge of the reservoir, passing bird hides and following the Nature Trail through the wildlife reserve and woodland path to reach a track which was once the main driveway through the Nanswhyden estate. The walk passes the ruins of Nanswhyden House and Fir Hill Manor which fell into ruin when its heir never claimed it. The route then follows lanes to Nanswhyden Farm via the ford at Trengoose and Colan Church where each member of the congregation would cast a palm cross into the Holy Well to determine if they would live another year. The route then circles the valley with views over the lake before descending via the mill at Melancoose to complete the circular walk.


great walk, well worth doing this one
Good walk. Did it at daffodil time

Vital statistics

  • OS Explorer: 106 (scan QR code on right to order from Amazon)
  • Distance: 5.2 miles/8.4 km
  • Grade: Moderate
  • Start from: Porth Reservoir car park
  • Parking: Porth Reservoir car park TR84JS. On the A3059, make your way to the crossroads with the water tower located a couple of hundred metres towards St Columb from Treloy golf club. Turn in the direction signposted for Porth Reservoir. Follow the lane to the bottom of the valley, and just as you start to ascend after the mill, the car park is on your left.
  • Recommended footwear: waterproof boots

OS maps for this walk

Click or tap on map for more info (blue=laminated)


  • Pretty woodland and lakeside scenery
  • Wildlife including birdlife, deer and badgers
  • Crumbling ruins of the great manor houses of the Nanswhyden estate
  • Panoramic views over the lake and valley from Nanswhyden farm


  1. Follow the surfaced path from beside the Fishing Regulations sign near the entrance to the car park, keeping ahead on the main path to reach the water's edge.

    Porth Reservoir is managed by the South West Lakes Trust as a mature coarse fishery with carp, pike, bream, tench and roach. Some of the carp weigh up to 32lb and the pike can weigh up to 24lb. The dam was built in 1960 and the lake contains around 500 million litres of water available to quench the hangovers in Newquay. The area around the lake is a designated bird sanctuary with bird hides and the surrounding woodland is used for the teaching of woodland crafts.

  2. Follow the path along the edge of the reservoir to the bird hide.

    The grey heron is an unmistakably massive bird with a 6ft wingspan and is most commonly seen in or near freshwater. The call of the heron is equally unsubtle - it is more like grating metal than the sound of birdsong. Although herons primarily eat fish, they will eat frogs, rodents, moles, ducklings and even baby rabbits! In Tudor and Elizabethan times, hunting herons with peregrine falcons was considered a royal sport which resulted in the birds being protected from peasants who might otherwise have caught and roasted them.

  3. Follow the path up the steps to a signpost. Turn left (signposted Footpaths and Nature Trail) and follow the path through the woods until you reach a sign for Fishing Pegs and Nature Trail.

    Many of the trees along the path are oak.

    For such a widespread tree, the oak is surprisingly inefficient at reproducing naturally. It can take 50 years before the tree has its first crop of acorns and even then, the overwhelming majority of the acorns it drops are eaten by animals or simply rot on the ground. Squirrels play an important part by burying acorns and occasionally forgetting a few, which have a much better chance of growing than on the surface.

    The older an oak tree becomes, the more acorns it produces. A 70-80 year old tree can produce thousands. As well as for squirrels, acorns are a really important food for deer and make up a quarter of their diet in the autumn. Acorns are high in carbohydrates and were also eaten by people in times of famine. Acorns were soaked in water to leech out the bitter tannins and could then be made into flour.

    The high levels of tannins make large amounts of oak leaves and acorns poisonous to cattle, horses, sheep, and even goats, but not to pigs as wild boar were adapted to foraging in the oak forests.

    Wood from the oak has a lower density than water (so it floats) but has a great strength and hardness, and is very resistant to insect and fungal attack because of its high tannin content. This made it perfect for shipbuilding, and barrels made from oak released preservative tannins into their contents.

    Oak was often associated with the gods of thunder as it was often split by lightning, probably because oaks are often the tallest tree in the area. Oak was also the sacred wood burnt by the druids for their mid-summer sacrifice.

  4. Follow the path to the right, signposted to the Nature Trail. When the surface path comes alongside, cross onto this (as it's less overgrown),and follow it to where a small path departs to the right just before the the birdhide.

    Look out for the information boards along the Nature Trail, starting with one on slow worms.

    During the summer months, slow worms can sometimes be seen basking in the sunshine, particularly on pieces of stone which act as a sunbed. Being reptiles, they don't generate their own body heat so they need to get it from an external source. Despite their resemblance to snakes, slow worms are lizards that have evolved to lose their legs. They are a good example of convergent evolution, where quite unrelated groups of animals have evolved to fill a similar niche. Slow worms are surprisingly long lived, and may exceed 30 years of age in the wild and over 50 years in captivity.

  5. Turn right onto the small path to reach a signpost, then turn left marked "Permissive Footpath", and follow the path until you reach a pedestrian gate in the corner of the fence on your right, marked as a permissive path through the Firhill Estate.

    The mature trees around the reservoir provide a habitat for Green Woodpeckers.

    Green woodpeckers are the largest and most colourful of the woodpeckers native to Britain and have a distinctive laughing "yaffle" call. The two species of spotted woodpecker are smaller and usually noticed from the drumming sound they make on trees. All of the woodpeckers bore holes in trees in which they nest, but only the spotted woodpeckers drill into trees in search of food, spending most of their time perched on a tree. Conversely, green woodpeckers spend most of their time on the ground, hunting for ants. The ants nests are excavated using their strong beak and ants caught on the barbed end of their long tongue. In fact, their tongue is so long it needs to be curled around their skull to fit inside their head.

  6. Turn right through the gate and follow the permissive path between the fences until you reach another gate which opens onto a track.

    The woods also provide cover for deer to hide during the day.

    The Roe Deer is unusual among hoofed animals as the egg is fertilised at the time of mating but then goes into suspended animation for several months - a process known as delayed implantation. This mechanism means that instead of being born in late winter, the young are born in early summer when food is more plentiful.

    In most species with delayed implantation, the mother sends out a hormonal signal to tell the embryo to wake up. However in the case of the Roe Deer, the embryo has a built-in egg timer which sends a chemical message back to the mother that it's time to resume the pregnancy.

  7. Go through the gate onto the track. Turn right and follow the track until it merges with another beside a Real Glamping sign.
  8. Bear right to join the track and follow it until ends at a pair of gates in front of a lane.

    The ruins half-way along on the right-hand side of the track are of Fir Hill Manor.

    Much of the valley surrounding Porth Reservoir was part of the large estate of the Hoblyn family known as Nanswhyden (meaning "Valley of the trees"). This once surrounded the elegant Nanswhyden House built in 1740s which was gutted by a fire in 1803. A new manor house, known as Fir Hill house, was built in the 1850s. In the 1960s, its owner died but his heir never accepted the claim, instead living in an RV in California with his sister. This created a 40 year legal impasse where his cousin - the next male family member - was unable to inherit the estate and restore the house, and so the house fell into ruin. Despite never taking his claim, the heir did change the will so that majority of the estate went to his two sisters on his death, rather than to his cousin. When their heir died in 2011, the legal dispute was settled, with the estate to be sold so the proceeds could be split between his elderly sisters and used to pay their medical bills in the US.

  9. Continue ahead at the barrier, and bear slightly left onto the lane (ignoring the track on the far left). Follow the lane to a gate into the churchyard.

    Blackbirds are one of the most common birds in the UK with a population of somewhere between 10 and 15 million. However, blackbirds were in steady decline from the 1970s through to the mid-1990s. The population has only relatively recently recovered.

    Blackbirds begin singing from around the end of January but it is normally the overkeen young males initially - the older, wiser males wait until March, pacing themselves for the singing period which continues into the early summer. Blackbirds have been shown to sing more during and after rain but exactly why is not yet known.

    Baby blackbirds usually leave the nest before they can actually fly then hop and scramble through the bushes. Their parents watch over them so don't attempt to rescue them.

    The reference in the nursery rhyme "sing a song a sixpence" to "four and twenty blackbirds baked in a pie" is thought to be to the 16th Century amusement (though not for the blackbirds) of producing a large pie which included an empty chamber. After the pie had been baked and was ready to be served, a trapdoor would be cut in the empty chamber and live birds were placed inside which would fly out when the pie was cut open. Live frogs were sometimes used as an alternative.

  10. Go through the gate into the churchyard and at the church door, bear right onto the path to another gate.

    Colan Church is situated close to Porth Reservoir, near Newquay. The first church known to be built on the site was in 1250 and the present church dates from 1360, initially built to a cruciform plan and expanded during the 15th century. It was dedicated to a 7th-century Welsh saint known as Collen or Colanus, who like many of the Celtic saints, settled in Cornwall before moving on to Brittany. In 1876, the church was in a dilapidated state, but thanks to the vicar and the Hoblyn family of Fir Hall Manor, the main tower was rebuilt in 1879 and by 1887, the church had been completely restored. It became the Hoblyn family church and some of the Hoblyns are buried there.

  11. Bear left onto the lane and follow it until you reach a junction to the right with a white signpost on the left.

    There are two holy wells associated with Colan church. One is directly opposite the churchyard gate and may have been the original sacred spring around which the churchyard grew. The other, beside the lane to Lady Nance was visited in a Palm Sunday tradition where members of the congregation would throw their palm crosses into the well. The superstition was that if the cross floated, the thrower would live for another year, but if it sank, the thrower's life expectancy was less than 12 months!

  12. Continue ahead at the junction in the direction signposted to St Columb and follow the lane until you reach a junction on the left, signposted to Tregoose.

    Before Christianity, the Pagan Celtic people of Cornwall worshipped wonders of the natural world. Where clean, drinkable water welled up from the ground in a spring, this was seen as pretty awesome. Where the springwater dissolved minerals, for specific conditions (e.g. deficiency in a mineral) or where the water was antibacterial, the water appeared to have healing properties. The sites were seen as portals to another world, and is why fairies are often associated with springs.

  13. Turn left at the junction and follow the lane until you reach a ford.
  14. Cross the bridge to the right of the ford, then bear left to rejoin the lane on the other side of the ford. Continue on the lane until it ends at a T-junction.

    In early spring, the bank on the opposite side of the bridge is covered in snowdrops.

    Snowdrops are a member of the onion family, and one of the earliest plants to flower. They use energy stored in their bulbs to generate leaves and flowers during winter, whilst other plants without an energy reserve cannot compete. The downside to flowering so early is that pollinating insects are more scarce, so rather than relying exclusively on seeds, they also spread through bulb division. Although it is often thought of as a native British wild flower, the snowdrop was probably introduced in Tudor times, around the early sixteenth century.

    The bulbs are poisonous but contain a chemical compound which is used in the treatment of early Alzheimer's, vascular dementia and brain damage. The plant produces another substance in its leaves which inhibits the feeding of insect pests. This is being researched to see if this substance can be introduced into other plants.

  15. Turn left and follow the lane a short distance, to a gate for Nanswhyden.
  16. Go through the gate and follow the track until it ends by a barn.

    If you're doing this walk in the morning, you may notice a layer of fog above the reservoir which then begins to clear during the walk.

    The layer of fog which forms above the land or water during the night is known as "Radiation Fog" as it is caused by the surface cooling (by radiating away energy as infra-red) during the night. This in turn cools the air close to the surface which reduces its ability to hold moisture and this condenses out as a fog of tiny droplets. Once the sun rises and the ground begins to warm up, the fog usually dissipates relatively quickly.

  17. At the barn, bear right into the farmyard and then bear left to follow the track between the buildings, to a gate.
  18. Go through the gate and follow the track to the bottom of a small valley. Cross the stream and follow the track uphill to a barn.
  19. Go through the gateway to the left of the barn and follow the right hedge three quarters of the way along the barn to where a tiny path leads up to the side of the barn. If the Public Right of Way here is impassible, note that the field just uphill of the barn has a gate in the bottom hedge which rejoins the Public Right of Way near direction 21.
  20. Bear right up the path and past the barn to reach a gate into the field ahead.
  21. Go through the gate and follow the right hedge to a pair of gates.

    If there are sheep in the field and you have a dog, make sure it's securely on its lead (sheep are prone to panic and injuring themselves even if a dog is just being inquisitive). If the sheep start bleating, this means they are scared and they are liable to panic. If there are pregnant sheep in the field, be particularly sensitive as a scare can cause the lambs to be stillborn. If there are sheep in the field with lambs, avoid approaching them closely, making loud noises or walking between a lamb and its mother, as you may provoke the mother to defend her young. Sheep may look cute but if provoked they can cause serious injury (hence the verb "to ram"). Generally, the best plan is to walk quietly along the hedges and they will move away or ignore you.

  22. Go through the gate ahead and follow the right hedge uphill beneath the overhanging tree to reach another gate.

    Clover is a native plant and a member of the legume (pea and bean) family. It is also sown as a fodder crop and as "green manure" as it improves soil fertility. The two most common species are known simply as white clover and red clover, based on the colour of their flowers, with the latter generally being a slightly larger plant.

    The flowers and leaves of red clover can be dried to make a sweet tasting herbal tea. In order to get a good flavour, this needs to be infused for quite a long time (around half an hour) until a deep amber colour develops. Fresh clover doesn’t work so well as the drying process breaks down the cell walls of the plant.

  23. Go through the gate and follow the right hedge to a stile in the corner of the field.

    The farm over the hedge on your right is called Treisaac which is from the Cornish word ysek meaning corn (and the ubiquitous tre for the farm). Its south-facing slopes of the valley were presumably a good place for arable crops. Port Isaac, although thought of as a fishing village, has similar origins (meaning "corn port").

  24. Cross the 2 stiles and follow the right hedge to a stile in the far hedge.

    Traditional grazing land such as this contains a diversity of wildflowers amongst the grass that provides food for pollinating insects.

    Bumblebees were originally called "humble bees" and this name was still in use until early 20th century. There is an urban myth that according to aerodynamics, bumblebees should not be able to fly, leading to statements by US presidential candidates such as:

    It's scientifically impossible for the bumblebee to fly; but the bumblebee, being unaware of these scientific facts, flies anyway.

    You may not be too surprised to discover this assertion was based on flawed calculations in the early 20th Century that neglected to include the bees flapping their wings. In fact, during flight, they beat their wings around 200 times every second. However, the buzzing sound they make is not from the beating wings but from the bee's vibrating flight muscles. On cold days, by using their flight muscles, the bees are able to warm up their bodies to temperatures as high as 30 Celcius. In spring, queen bumblebees need to visit up to 6,000 flowers per day to gather enough nectar and pollen to establish their colony.

  25. Cross the stile and follow the grassy track to a clearing with field gates either side and a track leading ahead past the cottage.
  26. Bear right to follow the track through a metal gate and continue to reach a lane.

    Across a few fields on the other side of the lane is the farm of Treloy. This is on the site of a manor house which is recorded as being owned by Lord Godric before 1066, and from the 13th Century until at least the Tudor period by the Arundell family.

    A Roman bowl with a fitting lid made of almost pure tin was found at Treloy in 1830, resembling vessels of stone found in West Cornwall. The bowl was only saved from being re-smelted by the intervention of Dr Borlase, who happened to be present when it arrived at the smelting works. It is inscribed with Roman numerals and has been dated to the fourth or possibly late third century. Alongside it, an enamelled Roman brooch was also discovered.

    There have been other finds from mediaeval, Roman and Bronze Age periods in the surrounding area. Many of these went to the Geology Museum but were dispersed in 1901. Some have turned up since in other collections such as a bulb-headed bronze pin which is now in Cambridge.

  27. Turn left onto the lane and follow it to the bottom of the valley, and uphill a short distance, until you see the sign for Porth Reservoir.

    At the bottom of the valley is an old mill called Melancoose which is from the Cornish mel an cos meaning "mill in the wood".

  28. Turn left at the junction and follow the track to return to the car park.

Help us with this walk

You can help us to keep this walk as accurate as it possibly can be for others by spotting and feeding back any changes affecting the directions. We'd be very grateful if could you look out for the following:

  • Any stiles, gates or waymark posts referenced in the directions which are no longer there
  • Any stiles referenced in the directions that have been replaced with gates, or vice-versa

Take a photo and email contact@iwalkcornwall.co.uk, or message either IWalkCornwall on facebook or @iwalkc on twitter. If you have any tips for other walkers please let us know, or if you want to tell us that you enjoyed the walk, we'd love to hear that too.

Please recycle your ink cartridges to help prevent plastic fragments being ingested by seabirds. Google "stinkyink" and click on "free recycling" for a freepost label.
If you found this page useful, please could you
our page on Facebook?