Open House - the weekend 'open doors' event - showcases all that is best about the capital's buildings, places and neighbourhoods. Derwent London is once again opening the doors of its Angel Building in Clerkenwell - see the soaring atrium with artwork by Ian McChesney and the stunning rooftop views across London. AHMM architects will be there to answer questions. Doors open: Sat 22 Sept 10am - 5pm and Sun 23 Sept 1pm-5pm