Tavium, or Tavia, was the chief city of the Galatian tribe of Trocmi, one of the three Celtic tribes which migrated from the Danube Valley to Galatia in present-day central Turkey in the 3rd century BCE. Owing to its position on the high roads of commerce was an important trading post. The site was successively occupied by Hittites, Cimmerians, Persians, Celts, Greeks, Romans, Seljuk Turks and Ottoman Turks. At the time of the Roman Empire, Tavium was an important crossroads and a stopping place on the caravan routes.

One of the few things we do know about Tavium was that there was metalworking, because coins have been found that were minted there in the early 1st century bearing the likenesses of Marcus Aurelius and Elagabalus. Copper, tin, iron and silver were mined in the nearby mountains. If we can draw parallels with other Celtic sites of the time, the smelting and stamping was done by a small group of artisans working in one or two stone huts.

In the temple at Tavium there was a colossal statue of Jupiter in bronze, greatly venerated by the Galatians. There was some doubt about the exact site of the city, but it is today generally believed to be the ruins situated close to the village of Nefezköy (today known as Büyüknefes), lying in a very fertile plain east of the Halys in the province of Yozgat.