 To connect Calton Hill with Princes Street, all these streets were swept away, and an elegant arch, called Regent Bridge, was thrown over the hollow, making the descent from Calton Hill into Princes Street easy and agreeable.A new jail to be built on Calton Hill had also been promoted at this time and a new bridge would make access more suitable.In 1813, Sir John Marjoribanks, the then Lord Provost of Edinburgh, revived a plan to build a jail on the slopes of Calton Hill.