Crystal Palace Dinosaurs listed buildings from 1973, extensively restored in 2002, and upgraded to Grade I listed in 2007. The models represent fifteen genera of extinct animals, not all dinosaurs. They are from a wide range of geological ages, and include true dinosaurs, ichthyosaurs, and plesiosaurs mainly from the Mesozoic era, and some mammals from the more recent Cenozoic era. Following the closure of the Great Exhibition in October 1851, Joseph Paxton's Crystal Palace was bought and moved to Penge Place atop Sydenham Hill, South London by the newly formed Crystal Palace Company. The grounds that surrounded it were then extensively renovated and
Crystal Palace railway station the terminus of a spur line from Sydenham. In 1856 the station was able to take through train services to Wandsworth via West Norwood and Streatham Hill, following the completion of the 746 yard (690 m) Crystal Palace Tunnel. Although relatively short, the tunnel was regarded as a major engineering achievement as it was cut ""through the same treacherous material [clay], through the hill on which the Crystal Palace stands, and immediately under one of the great water towers, a superincumbent weight of 2,200 tons which taxed in its execution all the skill and workmanship of the eminent contractors."" In