As I was contributing my share to WikiCommons I read the Wikipedia has a lot about this stele, that was found serving as a lintel stone in a mosque near the Kale.

The black basalt stele is 2.18 metres high and about a metre wide and belongs to a type which developed in the 10th century BC. It depicts the weather god Tarhunzas, holding an axe and a thunderbolt in his raised hands. Vines sprout from the ground to his left and grain to the right, similar to the İvriz relief. A very similar depiction of the same god appears on the relief in the village of Gökbez, some 22 km to the south. The figure is depicted with clothing, hair and beard of the Assyrian style. The winged solar disk, a traditional symbol of the ruler, hovers over his head.

On the right edge of the stone block is an inscription in Luwian hieroglyphs. On it the author, Muwaharanis, writes that he had the stele erected in honour of Tarhunzas and identifies himself as a king and son of king Warpalawas. John David Hawkins gives the following translation:

This Tarhunzas Muwaharanis [ma]de (?), the Hero, the King, loved by Tarhunzas (and) the gods, the son of Warpalawas, the Ruler, the Hero.[1]

Muwaharanis was the successor of his father Warpalawas on the throne of the late Luwian kingdom of Tuwana, a successor state of the Hittite Tuwanuwa [de], in the southern part of the modern Niğde Province. Since it is known that Warpalawas was reigning in 709 BC, the relief must date some time after that year. Thus the stele is the latest known and datable example such a relief and possibly the latest known Luwian inscription - only the Karatepe Bilingual might be later.