Peek inside this fascinating effort to map Britain's subterranean tubes – a deep sprawl of unrecorded infrastructure beneath our feet

Join us next month in a cosy pub to hear all about Ordnance Survey's latest project

Register Lecture A golden age of cartography is upon us. Only this time, it's satellites and tech firms' vehicles that are crossing the Earth's surface, compiling maps for their distant masters who are building geospatial services."