Its source and headwaters gorge are situated deep in the Dinaric Alps at the base of the Zelengora and Lebršnik mountains, under the Gredelj saddle. The source is at 1,227 m.a.s.l. First section of the Neretva course from source all the way to the town of Konjic, the Upper Neretva, flow from south to north - north-west as most of the Bosnia and Herzegovina rivers belonging to the Danube watershed, and cover some 1,390 km2 with average elevation of 1.2%.