Four Seasons Hotel

10 Trinity Square is a Grade II* listed building in London, United Kingdom, overlooking the River Thames at Tower Hill, in the southeastern corner of the City of London. Built in the Beaux Arts style, it is best known as the former headquarters of the Port of London Authority and is thus also sometimes referred to as the Port of London Authority Building.

Since 2017, it has been operating as the Four Seasons Hotel London at Ten Trinity Square.