Petropavlovsk is located in the south-western part of West-Siberian lowland, on the right bank of Ishym River. The city was founded in 1752 as one of  Russian fortresses which had been defended Kazakh nomads camp from jungars attacks.
The fortress was in the form of hexagonal with an area of 2 hectares. At the corners of the fortress there were bastions which were connected with each other with curtains. The total length of the fortress wall was 1.3 km. There were quarters, stables, officer houses, garrison church, powder-magazine and many other storages were inside the fortress.
Petropavlovsk was an important center of silk and carpets trade.