No surface trace remains. What local people could once describe in practical terms, as a stone-lined corridor entered through an opening beside a hut, has been absorbed back into the ground without apparent disturbance or collapse, quietly erasing itself.

The structure was a souterrain, an underground passageway of a type constructed widely across early medieval Ireland, typically for storage, refuge, or both. They were built rather than dug: the passage at Carhan was lined at its base with orthostats, large upright stone slabs, with drystone masonry laid above them to form the walls, and stone lintels laid across the top to create the roof. The passage ran east to west, and its entrance lay adjacent to the first of what appears to have been a group of huts. A. O'Sullivan and J. Sheehan, compiling their archaeological survey of the Iveragh Peninsula for Cork University Press in 1996, recorded the site from local information, suggesting the passage was described by people who had seen it themselves. That access is now gone. The ground shows nothing.