· The Overseers of New Gate prison have constructed a building over the Shaft that connects with the prison caverns.

· The building is 40 feet long and 30 feet wide, surrounded by a 2-foot-thick stone wall.

· The wall is made of hewn stones, laid side by side in two tiers, and bound together with iron cramps.

· The wall is 7 feet high and built on a stone floor, divided into two rooms: the invalid room and the passage room.

· A heavy iron gate has been placed at the mouth of the shaft for security.