Bridge four-lane highway on the upper level and a pair of railway tracks at the lower level. Tower Bridge in London is different example of a double-decked bridge, with the central section consisting of a low level bascule span and a high level footbridge. A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the Lake Pontchartrain Causeway and Millau Viaduct. A three-way bridge has three separate spans which meet near the center of the bridge. The bridge appears as a "T" or "Y" when viewed
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.