Prepare to crouch down, don a hard hat and possibly get spooked in what is the only publicly accessible system of its kind in England. These medieval vaulted passages were built to house pipes bringing fresh water to the city. Guides lead you on a scramble through the network, relating tales of ghosts, escape routes and cholera. The last tour is an hour before closing; they're popular – book ahead.
David Gee/Alamy
Underground Passages
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