You might not think learning the art of dry stone walling can turn you into a conservationist, but the funniest things turn up in stone built walls.

When restoring old crumbling heaps to their former glory, people have unearthed everyday objects dating back hundreds of years. From old bottles to ceramics and metal vessels, it’s all there. Walls play an important part for local wildlife too, providing a natural haven for nesting sites.

Dry stone walling has been used widely in British agriculture, since the early Middle Ages, for containing and protecting livestock. Ancient examples stretch across the globe, from Peru and Japan, to Iceland and Egypt. In Britain, there are still standing examples of dry stone walls and buildings developed thousands of years ago - such as Celtic Brochs and Bronze Age burial sites.

Handcrafted legacy

Today, existing walls are the legacy of professional wallers who first appeared in the 18th and 19th centuries. During the last decade, there has been a resurgence of interest in this most ancient of crafts.

Hundreds of volunteers are signing up for beginners and advanced courses in dry stone walling. Stuart Manson, secretary of the LHI funded Gower Hey Wood project, organised a volunteer event to restore an 18th century boundary wall.

The 6 metre long wall at Needhams Farm near Stockport had seen better days. Volunteers equipped with gloves, goggles and hammers, began by reassembling the stones which had come apart through decades of exposure to the elements.

By the end of the two-day training course, they had built a wall 1.5 metres high and 6 metres in length. “You could see you’d done something at the end of the day. A wall that your grandchildren can come and look at, seeing what granddad or grandma built,” says Stuart. “The walls will last maybe another couple of hundred years.”

Triangular formation

The volunteers used the common principle of dry stone walling - constructing tightly packed stones into solid walls, without using mortar. Large base stones make up the foundation and smaller pieces of stone are used to fill in gaps. The wall is wider at the bottom for extra stability and reaches an apex at the top.

When soundly built, they can last for centuries, as borne out by hundreds of old walls dotted around the British landscape.

Regional marks

Look closely at these natural boundaries, and you’ll find they are distinctive in style and pattern. Besides using different types of stone found naturally in areas around the UK, regions have developed their own characteristic style of build.

Cornish walls are formed with slate in a herringbone pattern, and wallers used earth infill for extra stability. This became a natural place for flowers and grasses to grow, hence the colourful nature of dry stone walls throughout the Cornish landscape.

Cotswold dry stone walls tend to be tightly packed due to the use of Oolitic limestone, which is a more flexible and relatively soft construction material.

The wallers of Derbyshire and North Yorkshire use sandstone, which is a more tricky material to handle, being coarse and difficult to shape into even blocks. Hence the characteristic irregular pattern, compared to more even walls in South Yorkshire.

Preserving flora and fauna

As dry stone walls become more popular, they have significant economic and environmental spin-offs. Government backing has seen an extra 1000 miles of wall preserved in Cumbria and the North East. The result, according to Defra, is a marked upturn in the numbers of previously declining bird species. Bittern, stone curlew, cirl bunting and lapwing are making a welcome comeback.

It’s not just good news for birds – a sound wall can support insects, bats, weasels and other wildlife. Plus there’s the benefit to wildflower and bee populations which have seen a sharp decline in the last thirty years.

Whether its for economic or environmental reasons, the restoration of dry stone walling is a welcome sign. Besides containing all manner of treasures for archaeologists, it’s sustainable, cheap and has a great impact on the environment. And that can’t be bad.