is an underground structure which is found in many Iron Age
settlements in Cornwall
. The purpose of a fogou is now unknown, and there is little evidence to suggest what it might have been. Their central location in settlements and the work which evidently went into constructing them is indicative of their importance, which may have been religious.
The etymology of the word fogou is straightforward: it derives from the Cornish ifócw meaning a cave.
A notable example of an unspoiled fogou is to be found at Carn Euny in Cornwall.