From North Greenwich underground we changed line at Canary Wharf to head to Island Gardens station. From here on, we used the Greenwich Foot Tunnel. The foot tunnel provide pedestrian links underneath the river Thames from Island Gardens to Cutty Sark and vise versa. It is open 24 hours daily and can be accessed by stairs or the lift at each entrance. The entrance/exit is housed in a circular dome-shaped building. Definitely one of London’s other secrets.