The ancient city, located in the Alaşehir district, which is approximately 110 km away from the city center of Manisa, became an important center during the reign of the King of Pergamon Attalus II Philadelphus. Because of this, the city was named Philadelphia. The city was called "Little Athens" due to the abundance of temples and festivals held in the city, especially in the Roman Period. The city, which preserved its importance during the Byzantine Period, was surrounded by walls in the 11th century after the Turkish Raids began. The center of the city is the place known as Toptepe among the people today. In places close to the acropolis, especially in the area called Gevurtepe, traces of the Protohistoric period can be seen.
The theater, temple, and stadium structures were partially unearthed during the excavations carried out in the early 1980s around Toptepe. However, since the excavations did not continue, it is not possible to see these remains clearly today. A gate belonging to the Byzantine walls and called the "East Gate" was unearthed during the excavations. This door is the entrance door. The gate is preserved with two towers, one with a semicircle and the other with a rectangular plan. It was covered by knitting during the Turkish Raids and was not used after this date. One of the 7 churches (religious centers) mentioned in the Bible is in Philadelphia. Since the Early Byzantine Period (VI century) St. Jean Church is in the city. In the construction of this church, which has three monumental piers, the column pieces of the first age architectural works, and inlaid stones were used abundantly.