Smugglers' Tunnels
Many villages on the southern coast of England have a local legend of a smugglers' tunnel; the entrances to most of the actual smuggler's tunnels have been lost or bricked up.
Some tunnel stories turn out to be very plausible, such as the tunnel at Hayle in Cornwall which really does seem to have been built specifically for smuggling. In other instances the tunnel either doubles as a storm drain or some other functional channel, or else is an extension of a natural fissure in the rock, as at Methleigh and Porthcothan.
Beith in North Ayrshire was a notorious haunt of smugglers at one time, and legend has it that a tunnel ran from the town centre down to Kilbirnie Loch.
Read more about this topic: Ley Tunnel, Subterranean Passages