BT Tower

The BT Tower dominates the Fitzrovia skyline with its cylindrical concrete form, a shape chosen by its architects based on the theory that round buildings were more likely to survive a nuclear blast. Construction began in nineteen sixty-one to serve as a critical hub for a microwave telecommunications network called Backbone. This system was designed to keep the government and military connected across the country if a war destroyed traditional cable infrastructure. Because of this vital role in national defense, the tower was effectively treated as a state secret for decades, and its existence was famously omitted from many official documents and maps.