Where: Westminster Bridge (opposite and across the bridge from the houses of parliament)
What: Situated on the south bank of the Thames, the main building overlooking the river was opened by King George V in 1922.
Once the Headquarters of the London County Council and also of the Greater London Council (or GLC, which was disbanded 1986) it now houses the london acquarium, a marriott hotel and the recently opened and much talked about Saatchi Gallery. The London Eye is outside too.
Nearest underground station: Waterloo or Westminster