Having survived the Blitz in World War II, the iconic Dome of St Paul’s Cathedral dome today remains among the highest in the world. Sir Christopher Wren was the architectural genius behind this feat of engineering and design. 365 feet high and weighing about 65,000 tons, the innovative dome was constructed in three layers – a hemispherical outer dome to dominate the skyline, a steeper inner dome, and a hidden middle brick cone. This triple-dome system allows the cathedral to support a 850 ton lantern and achieve a great height making it one of London’s most visible landmarks.