Trebinje is a town and municipality located in the Republika Srpska entity of Bosnia and Herzegovina. It is the southernmost city in Bosnia and Herzegovina and is situated on the banks of Trebišnjica river in the region of East Herzegovina. As of 2013, it has a population of 31,433 inhabitants. The city's old town quarter dates to the 18th-century Ottoman period, and includes the Arslanagić Bridge, also known as Perovića Bridge.