Promachonas (Greek: Προμαχώνας) is a village and a former community in the Serres regional unit, Greece. Since the 2011 local government reform it is part of the municipality Sintiki, of which it is a municipal unit. Population 252 (2001). A major border crossing with Bulgaria is located here. The Bulgarian town opposite Promachonas is Kulata. Promachonas-Topolnica is an important Late Neolithic settlement and cult site which straddles the Greek Bulgarian frontier a few kilometers from the community of Promachonas.
