Kostel, a quiet corner of the Kolpa with a castle

A municipality of 54 hamlets

According to SURS, Kostel has 604 people on 1 January 2026 across 56.1 km², and the biggest of its 54 settlements, Potok, has just 56 residents. It ranks among the five smallest municipalities in Slovenia by population. It recorded 4,266 tourist arrivals in 2025, nearly all of them drawn by the river. Together with Kočevje it forms the Kočevsko destination, the land of forests and bears in the wildest part of Dolenjska.

Kostel Castle

Kostel Castle watches over the valley from a rock above the Kolpa. With its market settlement it is, according to Visit Kočevsko, Slovenia’s second-largest castle complex and the only inhabited settlement of its kind. Its position made it part of the defence against the Ottomans, and in 1809 locals attacked the French soldiers stationed there, opening the armed phase of the biggest revolt against the French in the country. Since the 1990s it has been partly restored, and it gave its name and coat of arms to the municipality.

Swimming in the Kolpa

Clean, mild water. The Kolpa rises in Croatia’s Risnjak National Park, runs for 292 km and forms the border between the two countries. Visit Kočevsko says that in its upper reaches it winds between sheer walls and, beyond Fara, squeezes between steep wooded slopes. In summer it’s a swimming river, and its rapids draw rafters and canoeists. Since 2010 it has held the European Destination of Excellence title. There’s more on my page about the Kolpa river.

It’s an anglers’ river too. The water is rich in oxygen, with salmonids and cyprinids; in winter people fish for huchen, and through the year for brown trout and grayling on the fly.

If you are staying the night, see the best hotel deals in Kostel for your dates: the well-placed rooms go fast.

Little details in the valley

In the hamlet of Vas, a white willow about 100 years old and 23 m tall, its trunk split four ways, holds the riverbank in place. At Predgrad stands the pillory where thieves and adulterers were publicly punished until the first half of the 19th century. They’re small things, but they show how old these villages are.

How to fit it in

Kostel combines well with Kočevje and the Krokar forest, a short drive away. I’d give it a whole summer day, with a swim, a paddle and the castle, and sleep by the river so you can enjoy the valley in the quiet of the evening.

So you do not lose the morning at the ticket office, browse tickets and tours in Kostel on GetYourGuide.

If you are staying the night, see the best hotel deals in Kostel for your dates: the well-placed rooms go fast.