Disused railway tunnels just tempting the carefree and curious.

The abandoned Mersey road tunnel you’re not supposed to know about but still maintained in good condition as an emergency route and film set.

Joseph Williamson's eccentric excavations under Edge Hill.

The world’s first commercial wet dock, hidden away under the shopping heartland of Liverpool.

The WW2 bunker near the Town Hall, where the Battle of the Atlantic was co-ordinated.

The pirates’ and smugglers’ subterranean world under the streets of New Brighton, no longer a wartime munitions factory.

A lost lake under Water Street (where else?)

And why there is no atomic bunker under central Liverpool, with the nearest safe zone an hour’s drive away.

Ed Glinert, creator of the immensely popular Underground Manchester and Underground London zoom tours, unveils this trip below the streets of Britain’s greatest maritime city.