Trnovačko Lake, just outside the park and the borders of Bosnia and Herzegovina, is a glacial lake at an elevation of , is long and wide set amidst a huge amphitheater of rocky peaks. The lake is drained from the Maglic, the Volujak and the Bioc hill ranges. The north side of the lake, which is open, has the wooded Vratnice. The lake water is green-blue in color. The plan is to form another national park within the borders of Montenegro, which should protect rest of the mountain range of Magilć-Volujak-Bioč and Trnovačko Lake. These two parks in neighboring countries should form one large trans-boundary protection zone.