Cunning Cover-ups: London’s Best-hidden Ventilation Shafts Please register for rides on Eventbrite so we can limit numbers, link:  https://www.eventbrite.co.uk/e/cunning-cover-ups-cycle-ride-to-londons-best-hidden-ventilation-shafts-tickets-1049731654637 London’s network of tunnels (for tubes, trains and sewerage) needs a […]