Halligye is the largest and best preserved of all the fogous with one 20.7m curving passage out of 39m in total. It shows most of the characteristic signs: its entrance faces south east; it is associated with a round; it has side passages and creeps; it has narrow archways inside and, in addition has a 'stumble step' perhaps designed to trip up an attacker. A normal height person can stand throughout most of its length.
It is situated on the Trelowarren estate and, being home to some horseshoe bats, is closed in winter. A torch is essential.
The plan shows the original entrance facing north. The English Heritage site graphics suggest that the modern south eastern entrance might also have been the original entrance. Experience of other fogous suggests that this is correct.
In front of you as you enter the straight passage is a 0.5m high inner archway and, on your left, another 1.1m arch through giving access to the main curving passage.
The first 0.5m high arch requires a competent limbo dancer ...
... beyond it, the second arch is rougher and slightly taller.
The stumble step at the end of the curving passage is obvious, just before a low arch on the left hand side leading to the creep.
The modern entrance is deep, at the bottom of a flight of steps.