What attracted the ancient Greeks to the banks of the Don and the Azov region?

Colonization brought them there. The Greeks were looking for fertile lands and they found them. These territories were fertile. In this connection, the Greeks founded numerous colonies here: Tanais, Olbia, Chersonesus, Panticapaeum, etc. Thus, the Black Sea region became the object of Greek colonization in the 1st millennium BC. The Greeks, on the other hand, often contacted the local population (Scythians, Cimmerians, etc.). These were mainly trade and peaceful relationships.