OS Grid ref- SW 71322394
Halliggye Fogou (fogou is Cornish for cave) is situated on the Trelowarren Estate near Helston.
The monument consists of a long narrow tunnel leading to three chambers and sits within the earthworks of an Iron Age farming settlement. The passages have a stone roof and walls. It is the largest and best-preserved of the twelve surviving mysterious underground tunnels associated with Cornish Iron Age settlements. A window-like entrance which was dug in Victorian times supposedly by treasure hunters has since been filled in.
Sir Richard Rawlinson Vyvyan, the Victorian landowner published a comprehensive account for the Journal of the Royal Institute of Cornwall on restoration work carried out on the fogou. He listed finds as a vase containing ashes and a roughly made cup, both of Celtic manufacture, and animal bones possibly from a deer.
A series of small excavations were carried out by English Heritage in the 1980's mainly to clear debris from the passage to aid examination and repair work after routine ploughing of the field, when the blade of the plough breached the roof of the main chamber: this hole has since been turned into an entrance stairway for visitors. Pottery found during excavations has included local Iron Age cordoned wares and some sherds of Roman Samian ware from southern Gaul.
The fogou was used during the Second World War by the Manaccan Auxiliary Unit as an explosives and ammunition store. The fogou is also of importance as a winter hibernation site for Horseshoe bats, a protected species. Access to the fogou is therefore only possible between April and September.
Halliggye Fogou is owned by English Heritage and managed by the Trelowarren Estate.
Halliggye Fogou lies 5 miles to the south-east of Helston off B3293 roadf. Follow the signs for Trelowarren Estate. Park in the lay-by on the lane through the Trelowarren Estate. Walk up the hill and the entrance to the fogou is signposted through a gate.