UK Cave systems
Underground Boat rides
- King Arthurs Labyrinth - Sail along an underground river, through the great waterfall, and into King Arthurs Labyrinth.
- Canal Tunnel trip - Travel by boat through Islington tunnel on the Regent's Canal for approximately three quarters of a mile. When the tunnel first opened boats had to be pushed through by a process of "legging" where men lay on the boat and pushed against the walls with their legs.