When it was constructed by Sir Robert McAlpine in 1931, The Dorchester on Park Lane was one of London’s most innovative buildings. Reinforced concrete allowed the creation of large pillar-free spaces and gave the hotel a reputation for being a very safe building. Both Dwight D Eisenhower and Winston Churchill stayed there during the war. In the year 2000, the BBC dedicated an entire programme to the London Plane tree outside The Dorchester in the series Meetings with Memorable Trees.