Sutjeska National Park has an amazing hike to Lake Trnovačko that takes you over Maglić, Bosnia's highest mountain. It's honestly one of the most breathtaking hikes I've done in the Balkans. The only thing I'd compare it to is Prokletije. But it's definitely the toughest of the two. Some sections basically required light mountaineering. You don't actually need any gear—there are ropes set up at the difficult spots, but honestly check the anchors first because some of them looked pretty sketchy. If you're thinking about doing it, make sure you're up for the challenge. Here's what it looked like.

So here's the thing—the hike starts in Bosnia, but the lake is actually in Montenegro. You're basically crossing the border, but there are no border guards or official crossings or anything. There's a little hut by the lake where you check in with your passport and pay 1 euro. When I got to the park entrance, I actually double-checked with the staff about how legit this whole thing was. They said it's totally fine—that's just how it works here.

There's also a direct trail straight to the lake without climbing the mountain. It's way easier, but you don't get to see the really spectacular stuff. I'm not sure it's worth doing honestly.