What is the official designation of the building visible from the Morpeth Arms in a manner enabling spying?
SIS Building The SIS Building or MI6 Building at Vauxhall Cross houses the headquarters of the Secret Intelligence Service (SIS, MI6), the United Kingdom's foreign intelligence agency. It is located at 85 Albert Embankment in Vauxhall, a south western part of central London, on the bank of the River Thames beside Vauxhall Bridge. The building has been the headquarters of the SIS since 1994.
10 Trinity Square 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.