Is a hollowed out truncated cone or frustum.This glorious piece of architecture is some 20m in diameter. It is endowed with natural skylights and an internal water supply. At floor level colourful benched decks of red shale extend north and south; internally it is cluttered with fallen rocks like discarded furniture overturned as though someone left in haste. Located 340m due west of the communication tower at Airly. Named by John Fox on a Bush Club walk 16th November 2015.