The archaeological site of Oluz Höyük, located near the village of Gözlek, in the Çekerek river valley (called Zuliya in the Hittite times, and Skylax in the classical antiquity), is located on the fertile Gelgiden plain. The Oluz Höyük mound, almost circular in its horizontal cross-section, rises 15 meters above the plain. It is a significant site where five major cultural layers have been identified during archaeological work.
The first, chronologically youngest, layer comes from Hellenistic times (the 3rd - the 1st century BCE). The remains of stone houses and streets were found there. The most important exhibits from it are an iron helmet, local and imported ceramics, and bronze coins.
The second layer represents the Achaemenid culture (the 5th - the 4th century BCE), i.e. the Persian Empire, whose most important rulers were Darius I, Xerxes I, and Darius III. During the reign of Darius III, the Persians were defeated by Alexander the Great. This layer has not yet been fully investigated, but the remains of the road were found in it and the two stone bases of columns suggest that there were some important buildings in it. Among the exhibits discovered from this period, the most significant ones are: a glass seal, a cult vessel decorated with a clay camel head, bone sun symbols, and bowls.
The third layer belongs to the Phrygian culture (the 8th - the 6th century BCE). The rich collection of finds from this period includes a vessel in the shape of a woman's breast and a stone statuette. These exhibits indicate the existence of a cult of the mother goddess Cybele in the central Black Sea coast. Other finds are: an ivory seal and a crater, i.e. a vessel used to mix water and wine, decorated with figures of deer.
The fourth layer is from Hittite times (the 15th - the 13th century BCE). In Oluz Höyük it is represented by the stone foundations of a building, and among the exhibits found within the most important are: the bronze sickle blade, loom weights made of terracotta, as well as dishes and pots. These finds indicate that it was an important Hittite settlement.
The fifth, oldest layer dates back to the Early Bronze Age (3rd millennium BCE). It is true that no remains of buildings were found so far, but a stone casting mould, flint tools, and pottery shells were unearthed.
The surface surveys at Oluz Höyük began in 1999 under the leadership of Şevket Dönmez from the University of Istanbul. In 2007, archaeological excavations were started, focusing on the Hittite and Phrygian layers, also under the supervision of Professor Dönmez.
In 2019, archaeologists discovered a post office from the Persian period as well as a monumental road leading to a sanctuary and a linked hall with pillars. The sanctuary was a fire temple, characteristic for the Persian civilization. The archaeologists believe that the pillared hall, located just a meter away from the fire temple, served as a post office for the Persians. Dönmez claimed that the Persians designated specific locations to set up post offices, where they had well-rested horses and couriers to deliver important news across their vst empire, and the pillared hall is one of these post offices. The finds from Oluz Höyük are on display at the Amasya Museum.