Deep within the British countryside, a series of ancient and enigmatic underground caves continue to baffle experts. These thousands-of-years-old structures, known as fogous (pronounced foo-goos), are unique to this part of the world and their purpose remains shrouded in mystery.
These subterranean passages and caves, exclusive to west Cornwall, lead to unknown destinations. Despite their mysterious endpoints, it’s clear they served an important function in the distant past – even if we may never fully understand what that was.
Among the most well-preserved ancient settlements is Carn Euny, located at Sancreed, near Penzance. This site, inhabited from the Iron Age through to late Roman times, houses one of these perplexing underground tunnels.
The village features the remnants of stone dwellings dating back to the second to fourth century AD, with walls still standing up to a metre high in places. The heart of the village boasts its most captivating feature – a stone-walled underground passage.
Fogous, the Cornish term for cave, typically consist of a buried, usually corbelled stone wall, narrowing at the top and capped by stone slabs, reports Cornwall Live.
This intriguing type of Iron Age monument is found exclusively in the far west of Cornwall. While similar structures have been discovered elsewhere, very little is known about their origins, despite their presence for thousands of years.
The foundations of the caves are believed to have remained largely unchanged, resembling their original state when they were part of the surrounding settlements. The village of Carn Euny was first unearthed by tin miners in the early 19th century, but it wasn’t until 1964-72 that extensive excavations took place.
Over time, the site has suffered damage from stone-robbing and farming, making the overall layout difficult to discern. However, archaeologists estimate there were at least ten houses from various periods of occupation, dating back to the Iron Age.
Carn Euny’s fogou is one of two such structures under the care and protection of English Heritage. The largest and best-preserved is Halliggye Fogou, located on the Lizard peninsula.
Experts believe there are only about fifteen of these ancient structures in existence, with similar ones known as souterrains found in Ireland, Scotland, and France. Halliggye Fogou, also managed by English Heritage, is thought to date back to the fifth or fourth century BC.
Halliggye Fogou was once part of a small farming community, likely inhabited until the end of the Roman period. With its stone walls and roof, this complex of fogou passages is the largest and best-preserved of several mysterious underground tunnels associated with Cornish Iron Age settlements.
Visitors can delve into the mysterious and narrow passages of the fogou, a hidden world nestled within a type of settlement known as a round. A round is a small enclosure defined by banks and a ditch, typically housing small timber or stone houses, round or oval in shape, often dating back to the Iron Age.
Excavations have revealed that Halliggye, the site where the fogou is located, has been occupied since the fifth or fourth century, making it one of the earliest known examples of this kind of settlement. The fogou is situated in the north-west part of the round, with its entrance along a short open passage featuring its original sloping floor.
The passages of the fogou run entirely underground, containing several different sections built at various times, as discovered during excavations in the 1980s. The purpose of fogous has sparked much debate and numerous excavations over the years.
Win Scutt, properties curator in the west for English Heritage, shared with CornwallLive that there are three main theories about what these intriguing caves could have been used for. With advancements in modern technology, he hopes more information will be uncovered in the coming years.
Scutt suggests the fogou could have served as a refuge during times of trouble, or as a cold store or cellar for food storage. Another theory is that they may have held some sort of ritual significance, although Scutt considers this to be the least likely explanation.
Win Scutt explains: “They are an Atlantic phenomenon if you like. Fogou is a Cornish name but these types of structures have been found elsewhere and in Ireland they use a French word, souterrain, which means under the ground. They have also been found in Scotland.”
He believes that one of the reasons they are prevalent in Cornwall is due to the adaptation to the conditions and geology. He said, “I think one of the reasons they are in Cornwall is because they have adapted to the conditions and the geology. If you’re in Wiltshire for example, you don’t easily have the stone required, but I also think it was a cultural thing people did in West Cornwall, certainly in the Iron Age and through the Roman period.”
However, he added that another reason could be Cornwall’s distinct cultural differences compared to other places in the country throughout pre-history. He continued, “But we don’t really know much more than that about what they are for and that is partly because they haven’t been properly excavated under modern conditions and even then it would be difficult to determine.”