Hattusa Boğazkale, Yazılı Kaya, and Alaca Höyük are archeological sites east of Ankara and north of Yozgat. Boğazkale, the double walled city above the present village of Boğazköy, was known as Hattusas and was the capital of the Hittite Old Kingdom around 1700 B.C. The Hittites were perhaps the earliest Indo-European peoples to invade central Asia Minor along with the Luwites about 2000 B.C.
The area was already settled by proto-Hatti people who spoke an agglutinated language like Sumerjan and produced gold ornaments of remarkable artistry. Yazılı Kaya, with its bas-reliefs on the living rock, was one of the religious centers of the Hittites and nearby was the burial ground of the people. Alaca Höyük was a royal residence in pre-Hittite times (2400-2200 B.C.). Many silver, bronze and gold objects have been found there, some being household items; some such as sun discs and figures of stags were objects of worship. These can be seen in the above-mentioned museum in Ankara.
Hattusa,
Ask one of the guides to give you a tour (usually personal) or make sure you buy the one of the guidebooks.