The site of a fogou at Boden Vean, Cornwall, has been known for some time and was rediscovered in 1991 following the digging of a water pipe trench by the landowner (Mr Christopher Hosken).
The site was then planned and drawn by the Cornwall Archaeology Unit who concluded that it was the remains of a partially collapsed fogou.
Below is the info from rlaha.ox.ac.uk/archy/abst401.html
(this link now dead) but from a cache search on google it is possible to read the following....
Archaeometry 40, 1 (1998), 187-216
A geophysical survey was conducted at Boden Vean, St. Anthony Meneage, Cornwall, over the site of a buried chamber thought to be the remains of a souterrain or fogou. A combination of geophysical techniques was successfully applied including an experimental microgravity survey over the location of the buried chamber itself. Magnetometer survey revealed a complex palimpsest of archaeological activity extending throughout the surrounding landscape, centred on a rectangular ditched enclosure containing the fogou. A series of gravity anomalies were recorded in the vicinity of the latter which were consistent with the collapsed section of the feature recorded by the Cornish Archaeological Unit. Further gravity anomalies suggested the presence of additional void features, possibly related to the extended passages of the fogou.
If anyone requires further information on Boden fogou or the adjacent Bronze Age roundhouse they can contact James Gossip at the Historic Environment Service, Cornwall County Council on [email protected]