 Most of Bath's buildings are made from the local, golden-coloured, Bath Stone. The dominant architectural style is Georgian, which evolved from the Palladian revival style that became popular in the early 18th century. The city became a fashionable and popular spa and social centre during the 18th century. Based initially around its hot springs, this led to a demand for substantial homes and guest houses. The key architects, John Wood and his son, laid out many of the city's present-day squares and crescents within a green valley and the surrounding hills. According to UNESCO this provided ... "an integration of architecture, urban design, and landscape setting, and the deliberate creation of a beautiful city". Development during modern eras, including the development of the transport infrastructure and rebuilding after bomb damage during World War II, has mostly been in keeping with earlier styles to maintain the integrated cityscape.
