RATH & Man-made underground passage in Ballindreen Scotch

Mutton and maths, not ghost stories. The chamber has no door because it is a math chamber: a solid floor, a smooth roof and a narrow throat that swallows a man standing upright. The chamber is a container for the life of the tower above it. The tower is the visible part of the chamber; the chamber is the hidden part of the tower. Both are one instrument. A man may drop a marble into the throat and count the delay before the marble strikes the floor. That measurement is the chamber speaking. The chamber does not need to be believed. It needs to be measured.