Westminster Underground Station is a striking example of industrial architecture on the London Underground. Rebuilt as part of the Jubilee Line Extension in the 1990s, engineers excavated a 39 m‑deep ‘station box’ beneath Portcullis House, lowering the District and Circle line platforms and threading new escalators through a concrete diagrid. The station’s cavernous interior is clad in exposed concrete and stainless steel, with escalators crossing at 45° and lift shafts rising through the void. Platform edge doors and glass walls on the Jubilee line platforms reflect the design’s emphasis on safety and modernity. Completed in 1999, the station has won architectural awards and serves as a gateway to the Houses of Parliament and Westminster Abbey.