Kotlaničko Lake
Kotlaničko Lake is a natural mountain lake on Zelengora, located in a cirque formed by glacial activity, surrounded by the peaks Domoš (1,882 m), Prutača (1,817 m), Klek (1,899 m), and Zimovnica (1,742 m). It lies at an altitude of about 1,514–1,528 meters, within Sutjeska National Park. It is about 400–480 meters long and 120–200 meters wide, with a maximum depth of up to 10 meters.
It is pear-shaped, and the water has a naturally emerald-green color created by the reflection of underwater plants that cover almost the entire bottom. The lake is fed by springs, and the water flows underground to Pridvoričko Spring, which flows into the Neretva. It is home to lake char and the endemic triton, a rare amphibian. Kotlaničko is one of the most beautiful and least visited lakes on Zelengora, reached by a marked mountain trail from the pass above Orlovačko Lake.