tower weighs over .and has the largest glass floor in Europe. Southsea Southsea is a seaside resort and residential area of Portsmouth located at the southern end of Portsea Island. Its name originates from Southsea Castle, a seafront castle built in 1544 by HenryVIII to help defend the Solent and Portsmouth Harbour. The area was developed in 1809 as Croxton Town; by the 1860s, the suburb of Southsea had expanded to provide working-class housing. Southsea developed as a seaside and bathing resort. A pump room and baths were built near the present-day Clarence Pier, and a complex was developed which included vapour baths, showers, and card-playing and assembly rooms for holiday-goers. Clarence Pier, opened in 1861 by the Prince and Princess of Wales, was named after Portsmouth military governor Lord Frederick FitzClarence and was described as "one of the largest amusement parks on the south coast". South Parade Pier was built in 1878, and is among the United Kingdom's 55 remaining private piers. Originally a terminal for ferries travelling to the Isle of Wight, it was soon redeveloped as an entertainment centre. The pier was rebuilt after fires in 1904, 1967 and 1974 (during the filming of Tommy). Plans were announced in 2015 for a Solent Eye at the pier: a £750,000, 24-gondola Ferris wheel similar to the London Eye. Southsea is dominated by Southsea Common, a grassland created by draining the marshland next to the vapour baths in 1820. The common met the demands of the early-19th-century military for a clear firing range, and parallels the shore from Clarence Pier to Southsea Castle. A popular recreation area, it hosts a number of annual events which include carnivals, Christmas markets, and Victorian festivals. The common has a large collection of mature elm trees, believed to be the oldest and largest surviving in Hampshire and which have escaped Dutch elm disease due to their isolation. Other plants include the Canary Island date palms (Phoenix canariensis), some of Britain's largest, which have recently produced viable seed. Southsea is often mistaken as a town separate from Portsmouth, mainly due to the confusing Portsmouth & Southsea railway station name. The resort of Southsea previously had its own dedicated light railway line; the Southsea Railway and its own terminus, East Southsea railway station. The Southsea Railway and station were closed in 1914, with the station's name merged into that of Portsmouth's main railway station name