Snow Hill Tunnel

Snow Hill tunnel is a railway tunnel on the northern edge of the City of London which carries the up and down Snow Hill lines between City Thameslink and Farringdon stations. The tunnel runs beneath the Smithfield meat market and was constructed, using the cut-and-cover method, immediately prior to the building of the market. The tunnel opened on 1 January 1866.

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).