This was built in the years 1348-55 in the outer wall of the fortress. This was to give King Edward III a private water entrance to his apartments which was located in this period in or by the Lanthorn Tower. Although the name suggests a children's nursery It is more likely that the name derives from an apron on which a boat could rest at low tide. Defence for this tower was provided by two portcullises.
Richard II, Edward's successor, made only minor improvements to the Tower, but they did include the extension of Tower Wharf east from St Thomas's Tower, ending the use of the Cradle Tower as a watergate. It was subsequently used to accommodate less important prisoners. The lower chamber is open to the public and the story of the famous escape of two prisoners in 1597 is recounted there.