Ghost building

The modern information board reads:
These gardens are laid out as the footprint of the Chapter House and Cloister of the Medieval Cathedral which was destroyed by the Great Fire of London in 1666. The actual remains lie a few feet below.
The Chapter House and Cloister, designed by the royal mason William Ramsay in 1332, were among the first and finest examples of the 'perpendicular' style which was to dominate English architecture for the next two hundred years.
Both the octagonal Chapter House and the square Cloister were two-storeyed enabling the prominent buttresses at each angle to form 'a crown surrounding the casket within'. The Chapter Room, with its huge windows, was on the first floor above an open undercroft and it was here that the Chapter or governing body of the Cathedral held its meetings.