section_path: Geography/Topography
section_name: Topography
paragraph_text: Topography
  
  Budapest, strategically placed at the centre of the Pannonian Basin, lies on an ancient route linking the hills of Transdanubia with the Great Plain. By road it is 216 kilometres (134 mi) south-east of Vienna, 545 kilometres (339 mi) south of Warsaw, 1,565 kilometres (972 mi) south-west of Moscow, 1,122 kilometres (697 mi) north of Athens, 1,235 kilometres (767 mi) north-east of Rome, 788 kilometres (490 mi) north-east of Milan, 443 kilometres (275 mi) south-east of Prague, 343 kilometres (213 mi) north-east of Zagreb, 748 kilometres (465 mi) north-east of Split and 1,329 kilometres (826 mi) north-west of Istanbul.
  
  The 525 square kilometres (203 sq mi) area of Budapest lies in Central Hungary, surrounded by settlements of the agglomeration in Pest county. The capital extends 25 and 29 km (16 and 18 mi) in the north–south, east–west direction respectively. The Danube enters the city from the north; later it encircles two islands, Óbuda Island and Margaret Island. The third island Csepel Island is the largest of the Budapest Danube islands, however only its northernmost tip is within city limits. The river that separates the two parts of the city is 230 m (755 ft) wide at its narrowest point in Budapest. Pest lies on the flat terrain of the Great Plain while Buda is rather hilly.
  
  The wide Danube was always fordable at this point because of a small number of islands in the middle of the river. The city has marked topographical contrasts: Buda is built on the higher river terraces and hills of the western side, while the considerably larger Pest spreads out on a flat and featureless sand plain on the river's opposite bank. Pest's terrain rises with a slight eastward gradient, so the easternmost parts of the city lie at the same altitude as Buda's smallest hills, notably Gellért Hill and Castle Hill.
  
  The Buda hills consist mainly of limestone and dolomite, the water created speleothems, the most famous ones being the Pálvölgyi cave (total length 7,200 m or 23,600 ft) and the Szemlőhegyi cave (total length 2,200 m or 7,200 ft). The hills were formed in the Triassic Period. The highest point of the hills and of Budapest is János Hill, at 527 metres (1,729 feet) above sea level. The lowest point is the line of the Danube which is 96 metres (315 feet) above sea level. Budapest is also rich in green areas. Of the 525 square kilometres (203 square miles) occupied by the city, 83 square kilometres (32 square miles) is green area, park and forest. The forests of Buda hills are environmentally protected.
  
  The city's importance in terms of traffic is very central, because many major European roads and European railway lines lead to Budapest. The Danube was and is still an important water-way and this region in the centre of the Carpathian Basin lies at the cross-roads of trade routes. Budapest is one of only three capital cities in the world which has thermal springs (the others being Reykjavík in Iceland and Sofia in Bulgaria). Some 125 springs produce 70 million litres (18 million US gallons) of thermal water a day, with temperatures ranging up to 58 °C. Some of these waters have been claimed to have medicinal effects due to their high mineral contents.