Herzegovina
Herzegovina ( or ; Serbo-Croatian: "Hercegovina", Херцеговина, ) is the southern region of Bosnia and Herzegovina. While there is no official border distinguishing it from the Bosnian geographical region, it is sometimes asserted that the borders of the region are Dalmatia to the southwest, Montenegro to the east, Mount Maglić to the northeast, and Mount Ivan to the north. Measurements of the area range from , or around 22% of the total area of the present-day country, to , around 24% of the country.
Trebinje
The city lies in the Trebišnjica river valley, at the foot of Leotar, in southeastern Herzegovina, some by road from Dubrovnik, Croatia, on the Adriatic coast. There are several mills along the river, as well as several bridges, including three in the city of Trebinje itself, as well as a historic Ottoman Arslanagić Bridge nearby. The river is heavily exploited for hydro-electric energy. After it passes through the Popovo Polje area southwest of the city, the river — which always floods in the winter — naturally runs underground to the Adriatic, near Dubrovnik. Trebinje is known as "the city of the sun and platan trees", and it is said to be one of the most beautiful cities in Bosnia and Herzegovina. The city is economic and cultural center of the region of Eastern Herzegovina.