Mystery shrouds an ancient tunnel built more than two millennia ago. Halliggye Fogou in Helston is one of the more curious tourist attractions in the UK. The Iron Age underground chamber is believed to have been built in around the 4th and 5th century BC, and was used for at least 700 years. It is one of the best examples of a Fogous, from the Cornish word 'ogo' meaning cave, which are found only in the far west of Cornwall. What they were used for and why they were built is unclear.
Some archeologists have speculated that the caves were used to store valuables, while others argued that they served as refuges, or used for ceremonies and rituals. Whatever their true function, some have survived until this day. Halliggye Fogou is one of the best surviving examples and is situated within an earthwork enclosing a settlement, possibly a defended Iron Age homestead on the Trelowarren Estate, according to Heritage Gateway. It is a large, sprawling complex including a 20 metre long stone-lined chamber with a 28 metres long curvilinear passage branching off it, leading to a much smaller side chamber.
At its highest both are more than two metres, both at points they dip down into a claustrophobic 'creep'. Landowner Sir Richard Vyvyan explored the caves more than 100 years ago and found a vase containing ashes, a roughly made cup, and animal bones. Before it was taken over and run by English Heritage—which leaves entry free to the public—the Manaccan Auxiliary Unit used it during the Second World War as an explosives and ammunition store.
