Man-made underground passage in Garraun Upper

No visible passage remains, but a hollow inside the Garraun Upper rath still suggests that people dug beneath the ground and left a space large enough to be remembered. Holt called it a collapsed man-made underground passage in 1912, and that judgement gives the hollow more life than ordinary earth. The rath keeps its shape while the digging has vanished, as if the underground room withdrew when stopped being watched.