Museum of London, London Wall EC2

Union (Horse with Two Discs) was created in 2000 by British sculptor Christopher le Brun and one of the three bronze castings placed in the entrance of the Museum of London in 2005.
Horses and discs are recurring elements in le Brun's engravings, paintings and sculptures. Here they combine slightly uneasily - from the front you can't see the horse properly and when you look round the back all you can see is its arse.
If you google the sculpture you will note a very strong propensity by photographers to shoot it side on so the discs more or less disappear, or look alarmingly as though they are cutting the horse in half.
There is a very flowery article on le Brun here.