The Angel of Peace Descending
This is the Wellington Arch at Hyde Park Corner, and depicts the Angel of Peace descending on the chariot of war. I know this from the Wikipedia Entry which includes the fascinating snippet: One half of the arch functions as a ventilation shaft for the London Underground network. This causes on average three emergency calls each year to the London Fire Brigade from people believing there to be smoke coming from the arch when in fact it is warm air and dust from the underground network. So now you know.