55 King Street could be comfortably described as a good example of brutalism.  It was built between 1966 and 1969 to a design by Casson, Conder & Partners for the District Bank, which later became the Natwest Bank.  Sir Hugh Casson was the architect who laid out the Festival of Britain in 1951. This design won a competition for what was a £12million project.

The building is clad in hand-tooled, vertically ribbed Swedish granite.  It is no longer the North West Headquarters of Natwest and has recently undergone a comprehensive remodelling by Orbit Developments.  It claims to offer, "up to 70,000 sq ft of quality air-conditioned office space with some of the largest single floors available in this established business location.

"  It also offers an interesting and somewhat unusual feature. It has three basement floors which provide a secure strongroom and archive storage facility, once used to store gold bullion.