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Stockwell Tube Station is on Clapham Road, .
From the 1880s, lines in central London and the inner suburbs were built in twin tunnels, some 20 metres (66 ft) under ground, where a layer of clay made excavation relatively simple.
The first of its kind was the City and South London Railway which ran for 5.2 km (3.25 miles) from King William Street in the City and under the Thames to Stockwell.
This was planned as a cable-hauled railway but opened in 1890 as the world's first deep-level electric railway.
This and subsequent similar lines have since always been known as Tube railways.