Wow, what a response :-) My grateful thanks to all those who replied. Much though I'd have liked it to be a Temple of Excuses, it seems clear that it was Exeter House (once owned by Lord Burghley, Queen Elizabeth's money manager), which was being temporarily used because the PCC's usual home at Doctor's Commons had been burnt down in 1666 in the Great Fire. Thanks again to all . . . DaveB