King William Street opened on 18 December 1890 and was constructed from a large masonry station tunnel accessed from the surface by a lift shaft or spiral staircase. Two platforms were provided, one on each side of the single, central track —one for passengers entering and one for passengers leaving the trains, a system later referred to as the Spanish solution. The station tunnel itself is situated beneath Monument Street and runs east-west across King William Street, ending beneath Arthur Street. The approach running tunnels had sharp curves and steep gradients in order to dive underneath the River Thames while remaining under public rights-of-way, in particular Swan Lane and Arthur Street. The combination of station layout and poor alignment of the running tunnels severely limited the c