As a result, Jeddah came under the sway of the Al-Saud dynasty in December 1925. In 1926, Ibn Saud added the title King of Hejaz to his position of Sultan of Nejd. Today, Jeddah has lost its historical role in peninsular politics after Jeddah fell within the new province of Makkah, whose provincial capital is the city of Mecca. From 1928 to 1932, the new Khuzam Palace was built as the new residence of King Abdul Aziz in Jeddah. The palace lies south of the old walled city and was constructed under the supervision of the engineer Mohammed bin Awad bin Laden. After 1963, the palace was used as a royal guest house; since 1995, it has housed the Regional Museum of Archaeology and Ethnography. The remaining walls and gates of the old city were demolished in 1947. A fire in 1982 destroyed some ancient buildings in the old town center, called Al-Balad, but much is still preserved despite the commercial interest to tear down old houses (Naseef House, Gabil House) and build modern high-rise buildings. A house-by-house survey of the old districts was made in 1979, showing that some 1000 traditional buildings still existed, though the number of structures with great historic value was far less. In 1990, a Jeddah Historical Area Preservation Department was founded. The modern city has expanded wildly beyond its old boundaries. The built-up area expanded mainly to the north along the Red Sea coastline, reaching the new airport during the 1990s and since edging its way around it toward the Ob'hur Creek, some from the old city center. Jeddah is located in Saudi Arabia's Red Sea coastal plain (called Tihamah). Jeddah lies in the Hijazi Tihama (Arabic: تهامة الحجاز) region which is in the lower Hijaz mountains. Historically, politically and culturally, Jeddah was a major city of Hejaz Vilayet, the Kingdom of Hejaz and other regional political entities according to Hijazi history books. It is the 100th largest city in the world by land area. Jeddah features an arid climate ("BWh") under Koppen's climate classification, with a tropical temperature range. Unlike other Saudi Arabian cities, Jeddah retains its warm temperature in winter, which can range from at dawn to in the afternoon. Summer temperatures are extremely hot, often breaking the mark in the afternoon and dropping to in the evening.