According to inscriptions by Antiochus, Arsameia was the summer capital and administrative centre of the Kingdom, founded at the beginning of the 2nd century BC by Arsemez, a descendent of Kommadenes.

An embossed pillar of Mitras is at the ceremonial road at the south, and an undamaged relief of Mithridates I shaking hands with Heracles. In front of this is the largest known Greek inscription in Anatolia, and to the right is a tunnel descending to a depth of 158m through the rock. On the platform over the hill is a monument and palace of Mithridates I, the foundations of the capital, and excavations revealed numerous statue remains including a queen and the head of Antiochus.