The town of Petrich is the administrative, economic and cultural center of the Petrich Municipality. It is located in the southern part of the Petrich Hollow, at the foothiils of Belasitsa Mountain (200 m a.s.l.). Petrich municipality borders the municipality of Sandanski – to the northeast; municipality of Strumyani – to the north; the Republic of Macedonia – to the west and the Republic of Greece – to the south.
The river of Luda Mara flows through the town and the river of Strumeshnitsa draws its lands to the north. At the northern and southeastern foothills of the Gyaur Kalesi Hill (the Fortress of Bulgarians), south of Petrich, scientists have discovered remains of a Roman settlement (Gorni Bair locality) and one from the Middle Ages. On top of Gyaur Kalesi, there are the remains of a Medieval fortress that existed in the 5th-6th c. and the 11th-14th c., with its most flourishing period being the 13th-14th c. The fortress walls are 1.80 m thick, built of roughly cut stones with white and red mortar. The fortress was built to defend the Medieval Petrich located below.
It is assumed that the name of the town comes from the Greek πέτρα (stone). The town and its region were conquered by the Turks at the end of the 14th c., probably around 1382, and it became an Ottoman administrative and military center. The main means of livelihood of local population in the 14th-19th c. was agriculture (wheat, rice, maze, cotton, sesame, vegetables and fruits). By the end of the 13th c., Turkish population prevailed in Petrich. The town hosted a convent of the Rila Monastery in the 19th c. the church of Uspenie Bogorodichno was built in 1857, and the church of Sveti Nikola – in 1868. The Bulgarian Society of Petrich which later became the Bulgarian Municipality of Petrich, was founded around 1868. In 1873, it founded a cell school in a private house at Martin Quarter (closed in 1876) where the teacher was Agapi Voinov.
The town of Petrich was liberated from Ottoman Rule on October 27, 1912 by the regiment of Nikola Parapanov. A large part of Turkish population left at that point. In the period 1913-1925, many refugees from Vardar and Aegean Macedonia settled here instead. Petrich became the center of Petrich Region in 1920.

Map of the region