This is called The Mall. The Admiralty Arch is in the background.
Admiralty Arch is a landmark building in London which incorporates an archway providing road and pedestrian access between The Mall, which extends to the South-West, and Trafalgar Square to the North-East. Admiralty Arch is a Grade I listed building. Until recently, the building housed government offices, but in 2012 the government sold a 125-year lease over the building to a property developer for redevelopment into a luxury hotel.[
U.K.Trip2014019SmallU.K. Trip 2014