Sillyon’s Main City Gate is a structure situatedin the southwest part of the city. It consistsof a complex with a courtyard entry gate andtwo towers. It is called the “Main City Gate”because it is the largest known gate of Sillyonand because it is the only entrance that allowboth pedestrian and vehicular traffic. We encounterexamples of courtyard entry gates fromthe Archaic period in Pamphylia and from theHellenistic period in Side, Perge, and Sillyon.These gates are the result of the defense strategiesdeveloped due to the political developmentsin the region but lost their function inthe Roman period. Yet they became an importantelement of the urban landscape. In thisstudy, we examined all the details of the gateand tried to determine its position within thecity plan, especially regarding the city’s defense.It is suggested that the Sillyon exampleis the product of a tradition that was carriedout in Pamphylia in the Hellenistic period,such as on the gates of Perge and Side, and istransformed into a representative character dueto the periodic developments in the region.