Hattusa, also Hattuşa, Ḫattuša, Hattusas, or Hattusha, was the capital of the Hittite Empire in the late Bronze Age during two distinct periods. Its ruins lie near modern Boğazkale, Turkey, within the great loop of the Kızılırmak River.
Charles Texier brought attention to the ruins after his visit in 1834. Over the following century, sporadic exploration occurred, involving different archaeologists. In the 20th century, the German Oriental Society and the German Archaeological Institute conducted systematic excavations, which continue to this day. Hattusa was added to the UNESCO World Heritage Site list in 1986.
Wikipedia https://en.wikipedia.org/wiki/Hattusa
UNESCO Website http://whc.unesco.org/en/list/377
Address 19310, Turkey
Coordinates 40°0'57.495" N 34°37'6.448" E