Notes: "A fogou or fougou (pronounced 'foo-goo') is an underground, dry-stone structure found on Iron Age or Romano-British defended settlement sites in Cornwall. Fogous have similarities with souterrains or earth-houses of northern Europe and particularly Scotland including the Orkney Islands. Fewer than 15 confirmed fogous have been found." Source: Wikipedia.
The Boleigh Fogue is "considered to be one of the best remaining monuments of its kind in Cornwall," according to RoseMerrynWood. "...There is much debate about the original purpose of the fogou. Some believe they were ancient grain stores, others housing for cattle. Yet another theory purports that they were used as hiding places, and certainly there is some recorded evidence that the Boleigh Fogou may have given shelter to Royalists hiding from Cromwell’s followers in the 17th century." It seems more likely, though, that these fogues or earth houses were built for spiritual purposes.