The Hittite sites around Çorum are the main reason to come here, and all three can be done as day trips from the city — or combined into a single long day if you start early.
Hattusa (Boğazkale), about 85 km south of Çorum, was the capital of the Hittite Empire from around 1600 to 1200 BC. At its height the city covered 1.8 square kilometres and housed tens of thousands of people. The ruins are extensive: massive cyclopean walls, the remains of dozens of temples, and three great gateways — the Lion Gate, the Royal Gate, and the Sphinx Gate. The scale of the place only becomes clear once you're walking the perimeter circuit, which takes a good two hours on foot. It's a UNESCO World Heritage Site and one of the most important archaeological sites in Turkey.
Yazılıkaya is a rock sanctuary 2 km from Hattusa, easily combined on the same trip. Two natural rock chambers are carved with reliefs of the Hittite divine pantheon — more than 90 gods and goddesses in procession, dating to the 13th century BC. Chamber B has a particularly striking image of the king Tudhaliya IV held in the embrace of the god Sharruma. The carvings are in reasonable condition and the setting in the open rock is atmospheric.
Alacahöyük is 36 km from Boğazkale (about 50 km from Çorum) and less visited than Hattusa, which works in its favour. The site has a Hittite gateway flanked by two sphinx reliefs — different from the gate at Hattusa and arguably more evocative — plus extensive excavation trenches showing occupation layers going back to the Chalcolithic. The small on-site museum contains finds from the famous royal tombs, which predate the Hittite period by more than a thousand years.
Getting between the three sites is most easily done by car. Hire one in Çorum for the day, or negotiate a fixed rate with a taxi driver — agree the price beforehand and expect to pay around 600–800 TL for a full-day circuit. There is no reliable public transport. The road from Çorum to Boğazkale passes through rolling agricultural land and takes about 1.5 hours; from Boğazkale to Alacahöyük is another 30–40 minutes. Plan to leave Çorum by 8am to do all three comfortably.