Karlovo is a historically important town in central Bulgaria located in a fertile valley along the river Stryama at the southern foot of the Balkan Mountains. It is administratively part of Plovdiv Province and has a population of about 19,373, the mayor being Dr. Emil Kabaivanov.

The Stryama is a river in southern Bulgaria, an important left tributary of the Maritsa. It originates in the Balkan Mountains. The river is 110 kilometres in length and is the sixth longest in the Maritsa drainage, following the Tundzha (390 km), the Arda (290 km), the Ergene (281 km), the Topolnitsa (155 km) and the Sazliyka (145 km).