The terrain of Herzegovina is mostly hilly karst with high mountains in the north such as Čvrsnica and Prenj, except for the central valley of the river Neretva River. Other larger towns include Trebinje, Stolac, Široki Brijeg, Konjic, and Čapljina. Borders between Bosnia and Herzegovina are unclear and often disputed. The upper flow of the Neretva River lies in the northern parts of Herzegovina,
a heavily forested area with fast flowing rivers and high mountains. Towns like Konjic and Jablanica lie in this area, considered by many the most beautiful part of Bosnia and Herzegovina. The Neretva rises on Lebršnik Mountain, close to the border to Montenegro, and as the river flows towards west, it enters Herzegovina. The entire upper catchment of Neretva constitutes a precious ecoregion with many endemic and endangered species. Fast flowing emerald river carves its way through the precipitius karst terrain, providing excellent opportunities for rafting and kayaking, while the spectacular scenery of the surrounding mountains and forests is a challenging hiking terrain. The Neretva's tributaries in the upper flow are mostly short, due to the mountainous terrain: the Rakitnica River has cut a deep canyon, its waters being one of the least explored areas in this part of Europe. The Rakitnica River flows into Neretva upstream from Konjic. The Neretva then flows towards northwest, through the town of Konjic. The river enters the Jablanica Reservoir (Jablaničko jezero), one of the largest in Bosnia and Herzegovina. The lake ends near the town of Jablanica, known for the Battle of Neretva, marking a crucial victory of Yugoslav Partisans over the German army and its quisling allies during World War II. From here on, the Neretva turns southward continuing its course towards the Adriatic Sea. With mountains lining its shores gradually receding, the Neretva enters a valley where the city of Mostar lies. It flows under the well-known old bridge (Stari most) and continues now more widely flowing towards the town of Čapljina and the Neretva Delta in Croatia before emptying into the Adriatic Sea.
