The Thracian tribes Sinti and Sintians used to inhabit the area of the present-day region of Petrich in antiquity. They lived south of the Maedi tribes. It seems that the socio-economical relationships among those Sintis, who lived along the Struma River valley, were so advanced that several urban-like villages began to appear on their territories. Such a village could have been found in the area of Kojuh on the territory of the Rupite. The visitor can see some signs of the ancient village on the hill above the Strumeshnitsa River. An ancient necropolis, which is supposed to be the city of Petra mentioned by Titus Livius, has been found in the area of Medika. Later on, the research showed that there was a connection between the village in the area of Kojuh and the capital city of the Sinti tribe - Heracleum Sinticum.

Some artifacts from the village in the area of Kojuh show that people mainly used the Greek language, even though some official monuments were in Latin. The population consisted mainly of mixed Thracian-Greek families and probably there has been an existing Roman class there. The influence of the Mediterranean, favourable climate and numerous mineral springs, the natural protection, the political and economic stability of the region are a prerequisite for the development of dynamic cultural and economic life. The route from the Aegean Sea to the interior used to have great importance but unfortunately, it wasn’t marked on the ancient road maps. This route passed through the Rupelsko gorge, along the left bank of the Struma River and the Kresnensko gorge in order to connect Tesalonikios and Serdika.