The National Liberal Club's wine cellar is London's first tube railway

From Clive's Underground Line Guide to the Bakerloo:

The route of the Bakerloo includes the oldest attempt at a tube railway: the Waterloo & Whitehall Railway was authorised in 1865 to construct a pneumatic railway (that is, one where trains are pushed though a tunnel by air pressure) from Great Scotland Yard to Waterloo station.

The single cast iron tube, 3.89 m (12'9") in diameter, would have crossed the river by being laid in a ditch dredged in the bed of the Thames. Though work did start, a general financial crisis prevented additional capital being raised, and the work was abandoned in 1868, with the company being wound up in 1882.

The trench excavated at the northern end is now the wine cellar of the National Liberal Club.