Trebinje lies in the Trebišnjica river valley, at the foot of Leotar, in southeastern Herzegovina, some 30km from Dubrovnik (Croatia). The city’s old town quarter dates to the 18th-century Ottoman period, and Trebišnjica flows through it.
By the 2013 census 25,589 people are living in the town and 68,434 in the whole Region.
Trebinje is characterized by Mediterranean climate with hot summers (260 sunny days) and short warm winters. The average annual temperature in the city is 16.6°C, average January temperature is 8.3°C, while average July and August temperature is 26.5°C. Humidity and cloudiness are relatively low. It is interesting that Trebinje has warmer autumn than spring.