Tower Bridge as its northern landfall is in Tower Hamlets. The bridge consists of two bridge towers tied together at the upper level by two horizontal walkways, designed to withstand the horizontal tension forces exerted by the suspended sections of the bridge on the landward sides of the towers. The vertical components of the forces in the suspended sections and the vertical reactions of the two walkways are carried by the two robust towers. The bascule pivots and operating machinery are housed in the base of each tower. Before its restoration in the 2010s, the bridge's colour scheme dated from 1977, when
London Bridge Is Falling Down Dancing o'er The Lady-Lee. </poem> The oldest extant version could be that recalled by a correspondent to the "Gentleman's Magazine" in 1823, which he claimed to have heard from a woman who was a child in the reign of Charles II (r. 1660–85) and had the lyrics: <poem>London Bridge is broken down, London Bridge is broken down, The earliest printed English version is in the oldest extant collection of nursery rhymes, "Tommy Thumb's Pretty Song Book", printed by John Newbery in London (c. 1744), beginning with the following text: <poem> London Bridge Is Broken down, Dance over my Lady Lee.