Visit the Georgian headquarters of Britain's oldest heritage charity, The Society for the Protection of Ancient Buildings (SPAB), during London Open House Weekend.

London's biggest architectural festival gives everyone the opportunity to visit more than 600 buildings, new and old, many normally closed to the public - free of charge.

SPAB was founded by William Morris in 1877 to counteract the highly destructive restoration' of medieval buildings being practised by many Victorian architects. Today it is the largest, oldest and most technically expert national pressure group fighting to save old buildings from decay, demolition and damage.

For more information about Open House Weekend visit the website openhouselondon.org/london/