Old John is a folly atop the highest hill in Bradgate Park, Leicestershire, England. It was built in 1784, by Thomas Sketchley of Anstey as a mock ruin. It was adapted in the 19th century by the seventh Earl of Stamford and Warrington to serve as an observation tower for the practice circuit he laid out for his horses, along with the building of a stable block lower down the hill. It is well known for its "mug-shape" — there was a longer section of wall adjoining the tower after the 19th century extension but this reduced in size over the years leaving the present 'handle' shape.