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Trnovačko Lake: where it is and how to get there from Piva

· 3 min read

A dark blue lake in the shape of a heart lies in a forested hollow, seen from high on a grassy slope, with bare grey limestone mountains rising all round it.
Photo: Aktron, CC BY 3.0

Trnovačko Lake (Trnovačko jezero) is a glacial lake at 1,517 m. It belongs to Montenegro, in Plužine municipality and Piva Nature Park, and sits about 3 km from the border with Bosnia and Herzegovina. Many websites list it under Bosnia or Sutjeska National Park, because the shortest walk to it starts at Prijevor on the Bosnian side.

No road reaches the lake. You either drive round through Bosnia to Prijevor and walk about two hours, or walk five to six hours each way from Mratinje on the Montenegrin side.

What it looks like

The lake lies in a basin under the peaks of Maglić, Bioč and Volujak. The water is about 9 m deep, and a path of about 2.8 km follows the shore. Seen from the ridges above, the lake has the shape of a heart, as in the cover photo, which was taken from the slopes of Maglić. You won’t see that shape from the shore.

In July and August the surface water warms to about 18 to 20 °C, but it stays cold a few metres down.

Getting there from Piva: the Prijevor route

From the via ferrata bridge in Piva Canyon, the way to Prijevor is:

  • 7 km, about 10 minutes, to the Šćepan Polje border crossing, and across to Hum in Bosnia and Herzegovina
  • about 23 km from Hum to Foča
  • about 27 to 30 km south from Foča on the M20 to Tjentište, the centre of Sutjeska National Park
  • about 20 km of gravel road from just north of the Sutjeska visitor centre up to the Prijevor saddle at about 1,668 m

Šćepan Polje to Tjentište is roughly 50 km, about an hour by car. The road between Hum and Foča is in poor condition, so allow more. Bosnia has financed its reconstruction, with work planned to start in 2027. On top of the driving, waits at the Šćepan Polje border are usually 30 to 90 minutes, longest on summer Sunday evenings.

The gravel road to Prijevor takes about an hour. A normal car can manage it when it’s dry, and after rain you want a 4x4. There’s a park barrier on the way up where you pay the Sutjeska entry fee.

From the car park at Prijevor a marked path leads to the lake in about 5 km. It drops into a valley before climbing to the shore, so the walk back has climbs too. Published times for it run from 1.5 to 3 hours each way, so plan for the longer end if you walk slowly.

The path crosses the border into Montenegro at an unstaffed spot in the forest, marked by a sign. There’s no checkpoint, but carry your passport, because you’re walking from one country into another.

The long way from Mratinje

From the Montenegrin side you walk in from Mratinje, the village by the dam on the Piva canyon road. The path climbs through beech and pine forest and over the Carev Do plateau, with a lot of height gain, and takes five to six hours one way, so there and back is 10 to 12 hours of walking.

Fees

The Sutjeska National Park day ticket rose from 10 KM to 20 KM per person on 6 August 2026, which is about €10. That price covers the park’s outer protection zones. The price list has a higher tier for the core zone around the Perućica forest, so check at the barrier which ticket you need for Prijevor. Some older articles still give the 10 KM price.

Piva Nature Park has its own small entry fee for the lake, and its 2026 draft price list gives €2 per person.

When to go

June to September is the usual season for the walk. In July and August set off early, because the last part of the way back is uphill to Prijevor, and in the afternoon that means climbing in the heat.

Combining it with the via ferrata

Trnovačko Lake takes a full day from Piva. From the via ferrata bridge it’s about 2 h 15 of driving each way plus the border queue, and three to six hours on foot. That doesn’t fit on the same day as the climb, but it works well on the day before or after. Šćepan Polje, 10 minutes past the bridge, is on the way to Prijevor, so its rafting camps make a good base for both. From Plužine, add about 25 minutes each way.

Plan a day at Piva covers the climb day itself, and things to do near Piva Canyon lists other ways to spend a second day. If you’re crossing from Sarajevo, how to get to Piva Canyon has the route over the Šćepan Polje border.