Shropshire Tar Tunnel

Near Telford in Shropshire, England, the Tar Tunnel is one of 10 Ironbridge Gorge Museums.

In 1787, miners struck a spring of natural bitumen, a black, treacle-like substance. The eerie, brick-lined tunnel was a great curiosity in the 18th century, and today visitors can don a hard hat, enter the 365-meter tunnel and still see the tar seeping from the rock.

£2.50 per adult, £2.15 senior, £1.95 child up to 18 (and still in full-time education). Call (01952) 884391, www.ironbridge.org.uk.