The Saints' Way runs for 30 miles from Padstow to Fowey, and follows one of the likely routes of early Christian travellers making their way from Wales and Ireland to the Continent during the Dark Ages. Rather than risk a premature martyring on the rocks around Land's End, they would disembark their ships on the North Devon and Cornish coast and cross the peninsula, on foot, to ports on the south coast such as Fowey. The Bush Inn at Morwenstow is thought to be one of the stopovers from the North Devon ports. The route from Padstow to Fowey was in use before the Dark Ages which is evident from Roman coins found along the route. However it is thought that it was likely to have been in use even earlier still, in the Iron Age.

Over 160,000 species of butterfly and moth have been described and nearly 19,000 of these have been found in the UK. Butterflies are effectively a sub-group of moths that fly during the day. They have adaptations for this such as wings that fold flat against each other with a camouflaged underside to help them hide from predators when landed but a patterned upper surface to attract mates during flight. Whilst moths' feathery antennae are highly optimised for an incredibly sensitive sense of smell, butterflies can make use of vision so their antennae are more streamlined and are also used to measure air temperature.

The oldest moth fossils found so far are from the Carboniferous period 300 million years ago. By the Middle Triassic (age of amphibians - before the dinosaurs), moths had evolved their proboscis used to collect nectar from flowers. Day-flying butterflies were on the scene in the Late Cretaceous (when Tyrannosaurs were around). Originally it was thought day-flying was to avoid night-flying bats but it's now thought more likely that this was mainly to take advantage of the abundance of nectar that was originally targeted at bees.

A popular misconception is that a butterfly was originally called "flutterby". In fact, the name stems from the Old English word buttorfleoge which literally means "butterfly". The term "flutterby" is thought to have been coined by Shakespeare.

Exactly why butterflies were associated with butter is a bit of a mystery. One theory is that they were seen hovering over pails of milk and thought to be stealing or protecting the butter. Another is that the yellow brimstone was the species for which this name was first devised.

When a caterpillar is still developing, it grows a small group of cells - known as an imaginal disc - for each of the adult body parts it will need as a mature butterfly. When a caterpillar pupates, it digests itself, releasing enzymes which dissolve all of its tissues into a soup leaving only the imaginal discs. These then act as seeds from which the adult butterfly is resurrected.

Many butterflies taste/smell using chemoreceptors on their feet and antennae. They can detect a sugar solution (nectar) with their feet that they can feed on. Female butterflies also detect suitable caterpillar food plants on which to lay their eggs.

There are 33 regions in England designated Areas Of Outstanding Natural Beauty (AONB) many of which were created at the same time as the National Parks. In fact the AONB status is very similar to that of National Parks.

There is a single Cornwall AONB which was established in 1959 and is itself subdivided into 12 sections. 11 of these are stretches of the coastline and the 12th is Bodmin Moor.

Sandeels are small slender fish found shoaling around the beaches in Cornwall. If you put on a mask and snorkel, you're almost guaranteed to see some, often swimming around your feet.

The name is confusing as sandeels are not eels, just long, thin fish (like barracuda, but a lot smaller!). The sand part is because they burrow into the sand if alarmed. There are two main types present in Cornwall: Lesser Sandeels are the small ones you're likely to see by the shore, Greater Sandeels are chunkier and about the length of your foot; they can sometimes be seen shoaling in deeper water, occasionally joining in with a shoal of Lesser Sandeels.

Sandeels are a vital part of the food chain, supporting many sea birds including puffins and larger fish such as sea bass. Consequently they are a favourite bait for anglers, and in Cornwall a curved iron bar known as a vingler was traditionally used to snag buried sandeels.

Sandeels eat zooplankton and are therefore snookered by Global Warming causing phytoplankton to bloom early resulting in the zooplankton being undernourished. Industrial fishing for sandeels for use in fertilisers (e.g. "fish, blood and bone") has also damaged the population.

Rockpool fishing is quite a popular childhood pass-time as a number of species can be lured out from hiding places by a limpet tied on a piece of cotton (leave a trailing end as if anything swallows the limpet, very gently pulling both ends of the cotton will cause it to release the cotton-tied limpet from its gullet). If you are intending to put the creatures into a bucket: ensure it is large, filled with fresh seawater and kept in the shade; ideally place in a couple of rocks for the creatures to hide under; do not leave them in there more than a couple of hours or they will exhaust their oxygen supply; ensure you release them into one of the rockpools from which you caught them, preferably a large one (carefully removing any rocks from your bucket first to avoid squashing them). Species you're likely to encounter are:

• Blennies which are fish about 5-10cm long, often found hiding under rock ledges. They can change their colour from sandy to black within a couple of minutes in order to match their surroundings. They have strong, sharp teeth for crunching barnacles and will bite if provoked.
• Shore crabs and sometimes edible crabs which can also sometimes be found hiding under rocks (carefully replace any rocks you lift up). Shore crabs have a fairly narrow shell which is almost as deep as it is wide. They vary in colour from green through brown to red (the redder individuals are apparently stronger and more aggressive). Edible crabs have a much wider shell which resembles a Cornish Pasty and are always a red-brown colour. Both have powerful claws so fingers should be kept well clear.
• Shrimps and prawns - do you know the difference? Prawns are semi-transparent whereas shrimps are sandy coloured and generally bury themselves in sand.

Alexanders are a member of the carrot family and grow along roadsides in places similar to cow parsley. The leaves are more solid than the lacy cow parsley leaves and the flowers are yellow rather than white. The name arises because the plant was introduced to the UK by the Romans and was known as the "pot herb of Alexandria". It is also sometimes known as horse parsley.

Alexanders are very salt tolerant so they thrive in Cornwall's salty climate. They are just as likely to be found along coastal footpaths as along country lanes. New growth appears in the autumn so during the winter, when most other plants are dormant, it is a dominant source of greenery along paths and lanes in exposed coastal areas.

Another place that alexanders are commonly found is near the sites of mediaeval settlements, in particular religious settlements where they were cultivated by monks as a vegetable. In mediaeval cuisine they were used as an alternative to celery (which was a more bitter plant back then). It was traditionally one of the "pot herbs" that were added to stews and the dried seeds can also be used as a spice. Alexanders were particularly useful during lean winters as its new growth is available in the late Autumn, before many other spring greens.

All parts of the alexanders plant can be eaten and it is a good source of iron and vitamins A and C. The flavour has been described as somewhere between parsley and angelica. However, foraging alexanders is not recommended unless you are experienced at identifying it because novices can confuse it with hemlock (the most poisonous plant in the UK - just a few leaves from this can kill you).

Like its domesticated relatives, wild garlic grows from a bulb. To distinguish it from other wild plants from the onion/garlic family (such as the three-cornered leek), the species sometimes just called "wild garlic" (Allium ursinum) is often known by the name ramsons or broad-leaf garlic. The scientific name (meaning bear leek) is because the bulbs are thought to be a favourite food of brown bears on the European mainland.

Wild garlic can be preserved as a frozen paste for use as a cooking ingredient throughout the year. Simply whizz up roughly chopped leaves in a food processor with enough olive oil to make a fairly thick paste and then freeze this in an ice cube tray (or slightly larger silicone moulds if you have them). Standard cooking olive oil will do for this (it's a waste to use extra-virgin as the powerful garlic will mask its flavour). Turn out the frozen blocks into a bag and keep in the freezer. They can then be used as garlic "stock cubes", added just before the end of cooking.

From geography lessons at secondary school, you'll probably know that wave-cut platforms form where waves hit the cliff face and create a wave-cut notch into which the cliffs above eventually collapse. The reason the cliffs are eroded faster than the platform below them is more in the realms of physics:

• The energy from a wave is concentrated when it breaks against the cliffs; when waves are breaking onto the gently-sloping platform, their energy is more diffuse.
• On the platform, the force from the waves is spread along the breadth of platform as the tide recedes. However, the cliff face usually takes a beating not just at the very highest point of the tide, but also for some of the time either side.
• The tide rises and falls sinusoidally with time, in other words, it changes at its most slowly at high tide where it can spend a bit more time bashing the living daylights out of the cliff face.

Nevertheless, the platform does slowly erode. At Porthleven it is estimated that the platform is eroding at a rate of 1mm every 5 years.

The two most common pigeon species are the wood pigeon and feral pigeon (domesticated rock dove). Wood pigeons are larger than rock doves. Rock doves have an iridescent green/purple patch on their necks whereas adult wood pigeons have a white patch on their neck (although this is not present in young birds).

The feral pigeons living in urban areas are descended from rock doves that were originally domesticated as a source of food. Dove cotes were built to house quite a large number as there is not much meat on a pigeon. Later, these domesticated birds were also used as carrier pigeons. Escaped birds have thrived in the food-rich urban landscape where the stone buildings resemble the rock outcrops they have evolved to nest on.

Despite their native habitat being woodland, wood pigeons are able to thrive wherever there is food. They have fared better than most birds with intensively-farmed crops and are particularly fond of oil seed rape. They are able to hoover up food quickly (up to 100 pecks per minute) and stuff large amounts into their crop (e.g. around 150 acorns!). They then digest this overnight.

During the 21st Century, wood pigeons have been migrating into urban areas where garden feeding has attracted them. There has also been an exodus from parts of the rural environment where changes to farming practices (e.g. daffodil growing or energy crops) has made fields less attractive.

There is no biological distinction between "pigeon" and "dove" although "dove" seems to now be used for the more elegant species and "pigeon" for the more unexciting ones. Due to the Norman ruling classes, it's relatively unusual in the English language for the French/Latin word to be the vulgar form and the Norse/Germanic word to be the "posh" form. It's is likely that the reverse was true in mediaeval times: pigeon meat was considered super-posh and the French word was used for the young, tender birds of the species that were eaten.

During winter, from November to March, winter heliotrope is visible along the edges of roads and paths as carpets of rounded heart-shaped leaves.

Winter heliotrope is native to Sardinia and North Africa. It was introduced to Britain in 1806 but only the male plant. The female plant has subtly different flowers with more rays.

Despite only having the male form in the UK (is and therefore unable to produce seeds), it can spread vegetatively through its network of underground roots. A small fragment of root can give rise to a new plant which allows it to colonise new locations. Within less than 30 years of its introduction it had been recorded in the wild in Middlesex. Roughly a century later it has become one of the most common plants along roads and bridleways in Cornwall.

The name of the plant is Greek for "sun direction" because the flowers turn to follow the winter sun.

The leaf shape of winter heliotrope is similar to its close relative butterbur, but the leaf edges are more rounded than butterbur and the leaves are evergreen whereas butterbur puts up flowers before it has any leaves. Both plants spread via rhizomes (underground stems) and their broad leaves can crowd out other plants making them potentially invasive.

Barnacles are crustaceans, related to crabs and lobsters. After a planktonic stage, they settle on a rock and never move again. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises. It is thought barnacles probably have the largest penis to body size ratio of the animal kingdom.

Seaweeds are algae and rely on sunlight to produce energy via photosynthesis in the way terrestrial plants do; they therefore thrive in shallow water where the sunlight penetrates. On the shoreline, you're likely to see brown bladderwrack and red dulse on exposed rocks; within rockpools, green sea lettuces and red coral-like seaweeds. At very low tides, or if you wade into the water beside rocks, brown ribbon-like kelp is common, which is a favourite hiding place for many fish such as bass, pollack and wrasse.

No seaweeds are known to be poisonous and several are eaten raw, cooked or dried. Seaweed is quite rich in iodine which is an essential mineral, but in very large doses is toxic, so excessive consumption are not recommended. A number of food additives such as alginates, agar and carrageenan are produced from seaweed and used as gelling agents and emulsifiers in many processed foods.