The European headquarters of Bloomberg has won the Riba Stirling prize for architecture.
The Royal Institute of British Architects gives out the award each year to the UK's best new building.
The building, which is in Bank, is the world's most sustainable office and largest stone building in the City of London.
It beat the likes of Bushey Cemetery and the New Tate St Ives to the prize.
The Bloomberg HQ was the 23rd recipient of the prize and the design by Foster + Partners was described as having a "restrained exterior and dynamic interior to encourage collaboration".
"Bloomberg is comprised of two buildings connected by a bridge. Each sit either side of a new public arcade, which re-establishes an ancient Roman road.
"This complex scheme also incorporates new access to Bank Underground station, cafes and restaurants, and a museum displaying the Roman Temple of Mithras, which was discovered on the site 60 years ago."
Building architects have managed to create an exterior that sits well with its surroundings, whilst also creating three new public spaces, which contributed to it winning the prize.
RIBA President Ben Derbyshire, said: "After vigorous debate, the jury reached a unanimous decision - Bloomberg's new European HQ is a monumental achievement.
"The creativity and tenacity of Foster + Partners and the patronage of Bloomberg have not just raised the bar for office design and city planning, but smashed the ceiling.
"This building is a profound expression of confidence in British architecture - and perfectly illustrates why the UK is the profession's global capital."