Megaproject as Keyhole Surgery: London Crossrail

London's east–west Crossrail is a civil engineering megaproject designed to produce a minimum of visible change at surface level. The paper explains the origins of Crossrail's 'keyhole surgery' approach, describes the station design process and considers its outcomes in a review of all eight subterranean stations with their twelve surface ticket halls along the central London section between Canary Wharf and Paddington. The strategy is compared and contrasted with Frank Pick's design thinking for London Underground and with the closer precedents of Paris's RER Ligne A. We show how the discreet keyhole concept has to be balanced against the requirements of (a) glazed façades to bring daylight into interior circulation spaces, and (b) design and management of exterior circulation spaces, given the increases in footfall anticipated around each ticket hall when Crossrail opens in 2018. Urban design of station settings remains unfinished business.