Ghadames or Ghadamis ɡəˈdæmᵻs (Berber: ʕadémis; غدامس, Libyan vernacular: ɣdāməs, Latin: Cidamus, Cydamus, Gadames) is an oasis Berber town in the Nalut District of the Tripolitania region in northwestern Libya. The indigenous language of Ghadames is Ghadamès, a Berber language. Ghadamès, known as 'the pearl of the desert', stands in an oasis. It is one of the oldest pre-Saharan cities and an outstanding example of a traditional settlement. Its domestic architecture is characterized by a vertical division of functions: the ground floor used to store supplies; then another floor for the family, overhanging covered alleys that create what is almost an underground network of passageways; and, at the top, open-air terraces reserved for the women. Ghadames lies roughly to the southwest of Tripoli, near the borders with Algeria and Tunisia. Ghadames borders Illizi Province, Algeria and Tataouine Governorate, Tunisia. The oasis has a population of around 10,000, mainly Berbers. The old part of the town, which is surrounded by a city wall, has been declared a UNESCO World Heritage site. Each of the seven clans that used to live in this part of the town had its own district, of which each had a public place where festivals could be held. Ghadames has a hot desert climate (Köppen climate classification BWh) with long, extremely hot summers as average high temperature is around 41 °C (105.8 °F) in July, the hottest month of the year as well as short, warm winters. The town receives little precipitation throughout the year as average annual precipitation is only 33.1 mm (1.30 in). It has been suggested, based on archaeological evidence, that this area has been settled since the 4th millennium B.C., and is one of the oldest pre-Saharan settlements. Its situation near a water source in the middle of a desert would have made it an important spot for anyone seeking to settle in the area. The first written records about Ghadames date from the Roman period when the settlement was known as Cydamus, from which modern Ghadames derives its name.