Time Out says
Get really stuck into the nooks and crannies of Blackfriars in this timed treasure hunt for all ages. Pick up a map from one of the two start points within the allotted time slots and get solving straight away to see whether you can beat other teams and win prizes from the likes of The View from the Shard and Thames Clippers. Each team's score is calculated according to their average clue-solving speed, so you can choose whether to be a tortoise who solves loads of clues or a hare who prefers to use their feet than their head.
Pick up maps at ASC Studios or on the concourse outside Blackfriars Station on its south side (near the Founders Arms) between noon-2pm Mon-Fri, 10am-4pm Sat & Sun.