Kolpa River Swimming Holiday

Kolpa River is one of the cleanest and warmest freshwater rivers in Europe and it offers an excellent open water swimming destination in the summer months. Kolpa springs from a small turquoise karst lake in the Croatian Risnjak National Park at the mountainous region of Gorski Kotar. The river source is not far away from the Adriatic sea in Istria. As the river flows east towards the Danube river and Black sea it forms a natural border between Croatia and Slovenia. The total river length is 292km with the Slovenian part stretching 113km.
Trip details:
  • Duration: 4 Days (3 Nights)
  • Tour Type: River Swimming
  • Accommodation: Hotel in Metlika, Slovenia
  • Average Daily Distance: 5-6 km
  • Level: Most level swimmers (see FAQs for details)
  • Escort: Three mini-rafts, canoes or kayaks
  • Water temp: 24-25 (°C) | Air temp: 28-30 (°C)

Kolpa River – Wild Swimming Adventure (from Mill to Mill)

We are based in the Bela Krajina region in southern Slovenia in the small town of Metlika. This region is often described as the longest riviera in Slovenia and it was voted as a European destination of excellence. Kolpa river is just around the corner which serves us as a great base for our daily swimming trips.

This river trip is suitable for most levels of swimmers (please check our FAQs for speed details), with three separate escorts for the safety and enjoyment of all guests. No motorized boat traffic is allowed on the river, so we will see other people in canoes, kayaks and mini rafts.

Tour Highlights

– Swim down river from watermill to watermill in the warm and clear freshwater,
– Explore Kolpa Nature Park through several gorges and valleys,
– Discover the Slovenian Bela Krajina region and it’s natural beauties,
– Taste local cuisine and traditional dishes,
– Walk along the river.

Included in the price
A complete guided trip led by a local guide, minibus (van) transport to swimming locations, full safety escort on every swim, technique and stroke tips, and accommodation for the duration of the trip (breakfasts included).  Each guest receives a silicone swim cap and safety briefing. We provide shared drinking bottles while you swim.

Limited fins, tow floats, and other swimming gear will be available for use. If you prefer your own, please bring it with you. Please bring your water shoes (aqua shoes) for walking in and out of the river and around watermills (dams).

Additional cost
Travel to/from location, lunches, dinners, local tourist tax (paid at the hotel reception), single supplement 100 Eur.

Kolpa River in the press
Crystal clear waters: Here are 6 of Europe’s cleanest river swimming spots

Photo Gallery

Swimming Kolpa River Photos 2023



Video clips


Hotel Bela Krajina is a good quality and locally operated boutique hotel located in the centre of Metlika town (Slovenia), just across the border from Croatia. Accommodation is based on double and twin rooms with en-suite facilities. There are also single rooms for single use available.

It offers 25 modern air-conditioned rooms with free Wi-Fi, parking and a delicious continental breakfast. The hotel also has its own bar and restaurant with a rich selection of house specialties and traditional dishes.

Campsite Podzemelj
For those looking to camp in clean nature, owners also operate a campsite on the Kolpa river.

Extended stay
If you require additional nights’ accommodation before or after our tour please book directly with the hotel, quoting Strel Swimming group.

Hotel’s contact info
[email protected], Tel: +386 4 572 91 00

Hotel Bela Krajina photos








Day 1
We meet at 20.00 (pm) at the hotel lobby for the trip briefing. We go through the trip’s plan and you get to meet other fellow swimmers. Dinner at your choice. We can organise and recommend a venue for an evening meal.


Day 2
We take a short 20min drive to Kolpa river bank. Before we start our first swim, we do a short 200m acclimatisation swim to make sure everyone feels comfortable swimming in the river. Our first mill-to-mill 2.5km swim takes us from Adlesici (Old Barn dam) to Podbrezje (Kuzma farm dam). The river width is about 100-150m and we follow the spectacular flora and fauna of the protected Kolpa Nature Park.

At Podbrezje we sit down to have lunch overlooking the beautiful river valley. For those interested in history, you will have a chance to look at one of the oldest Slovenian watermills including a sawmill wheel. The mills on Kolpa river (a total of 48 were built in the 18th and 19th century) are an important part of Slovenian cultural heritage and today only two remain active, some remain open to the public.

After an afternoon break, we go back into the river, starting at Fuckovci, where the river steadily flows all the way to Griblje dam. The total swimming distance is about 3.5km with a current assist. On the way, we usually pass local river swans and ducks while hearing birds singing from the trees. On arrival at Griblje dam, we enjoy a local traditional dinner alongside the river bank. Drive back to Metlika.


Day 3
After a good overnight rest and warm breakfast, we make our way back to the river to continue our wild swimming adventure! We jump back into warm Kolpa at Griblje dam to swim 3.3km towards the Krasinec dam, one of the most scenic dams on the river.

The river valley in this section is incredibly peaceful and green. You hear nothing but birds and will often spot fish underneath you. Kolpa is rich with local fish and we often meet some on our journey. Overall, there are over 40 different fish species living in the river.

At Krasinec dam we have a chance to look at your swim stroke and share some useful tip. Lunch at the local restaurant or picnic on the river’s bank. Before we start the afternoon swim you can try a natural massage under the river stream at the watermill. All you need to do is lie under the river fall at the right place and enjoy the massage!

Our afternoon swim takes us from Otok (Island) mill to Krizevska village mill covering a distance of 2.5km. On the way, we are joined by the Lahinja River at the Big Berry confluence. We follow the lush greenery as we navigate down the crystal-clear Kolpa River stream. For most of the swim, you are able to see all the way to the bottom of the river’s bed. On arrival at Krizevska village dam, we have a drink and make our way back to the hotel. Video analysis before dinner with some good tips to help you improve your stroke technique. For the evening meal, we recommend dining out at one of the local restaurants in the old town of Metlika and visit one of the wine cellars. This region is known for producing excellent wine.


Day 4
For our final day, we head back to Kolpa’s Nature Park to do the longest swim on the trip (4km). We join the Kolpa at Vukovci mill and swim all the way to Vinica dam. On the way, we pass two other mills at Ucakovci where we need to make two short walks around the dams. These short stops are a great way to stretch our legs and rehydrate during the swim. For everyone, it is also a chance to take a break or make the swim shorter if you want. Our escort team follows us on the river as well as on the road. As we approach the Vinica village there is a small bridge and campsite where we aim to exit on the left side. Drive back to the hotel. The trip finishes at around 14h.

Swimming info

Swimming Info
Google Map

Swimming distances (From Mill-To-Mill)

Swimming Locations  Distance
Acclimatisation swim   0.2 km (0.1 miles)
Adlesici mill – Podbrezje mill   2.5 km (1.5 miles)
Griblje mill – Krasinec mill   3.3 km (2.0 miles)
Otok mill – Krizevska vas mill   2.5 km (1.5 miles)
Vukovci mill – Vinica mill   4.0 km (2.5 miles)
Total estimate   16.0 km (10.0 miles)


Month Kolpa river (˚C/F) Air Temp. (˚C/F)
July 24 / 75 28 / 82
August 25 / 77 30 / 86

If you would like to skip one of the swims or make it a bit shorter, there are options available.

NOTE! It is highly unlikely, but in case there would be a substantial water level and flow increase during your trip, we will find an alternative venue to swim for this day.

The water temperature during July and August ranges between 24-26C on the places where we swim, so wetsuits should not be required. However, if you feel more comfortable wearing a wetsuit, please bring it with you. We will help you dry it and have it ready for the next day.

We have limited wetsuits on location to use, but bear in mind that they may not be your perfect fit. If you intend to swim wearing a wetsuit, we recommend you bring your own that you know is comfortable.

Water shoes or Aqua shoes
On this trip we cross several river dams where we need to get out of the river and walk around to the next entry point. You need to have good water shoes that you can put on and off easily to get into and out of the river. There may also be stones and rocks in the river at exit and entry points and shoes with a good grip will help you with your footing. Open flip-flop sandals are not the best option. Please bring something like Aqua Water Shoes.

Walking Conditions
We do short walks on this trip along the river, usually after lunchtime to stretch legs and we visit some local sights such as: watermills, castles, restaurants, etc. We advise you to bring a good pair of light walking shoes (trainers) as there are some uneven rock surfaces.

Group size
Up to 16 people.

Essential Equipment
In addition to normal items, we recommend to bring the following: at least 2 swimming costumes (one wet, one dry), at least 2 pairs of swimming goggles (one clear and one tinted recommended), sweater/fleece, towel, hat, small daypack, jacket, waterproof sun cream, walking shoes (trainers) and aqua shoes (water shoes).

Weather Caveat
Your safety is of the utmost importance to us. In the event of adverse weather conditions at any of our swimming locations, we may need to adapt our itinerary or amend some of the swims described above.  Our team always includes at least one local guide who knows the safest and best places to swim, so rest assured you won’t miss out!

Environmental and safety factors in Lakes
Slovenian lakes are clean, freshwater lakes. As with any open water activity, swimmers should always be aware of the risk of Weil’s Disease (Leptospirosis).  The risk of infection in Slovenia is extremely low, but guests should inform their swimming guides immediately if they feel unwell. The incubation period for the disease can be several weeks, so contact your GP immediately if you feel unwell after you have returned home.

Travel info

To get to Metlika (Slovenia) please see the options below.

Metlika has a train station that connects both cities Ljubljana (Slovenia) and Zagreb (Croatia) and you can travel daily with several trains.

1) Travel by Bus or Train

a) By Bus from Zagreb, Croatia to Metlika, Slovenia. https://www.arriva.com.hr
b) By Bus from Zagreb to Karlovac (cca 5 Eur) and then a taxi from Karlovac to Metlika (cca 25-30 Eur).
c) By Train from Ljubljana to Metlika by train: https://potniski.sz.si/en/ (cca 10 Eur).
d) By Train from Zagreb to Karlovac (1st leg) and then Karlovac to Bubnjarci (2nd leg) with a final destination Metlika (cca 8 Eur). https://prodaja.hzpp.hr/en/

2) Travel by Air
Both Ljubljana (Slovenia) and Zagreb (Croatia) airports offer hourly bus or shuttle services to city centers where you connect to a train or bus for your connecting journey to Metlika.

a) To Zagreb airport and take a taxi to Metlika, Slovenia. The cost is about 100 Eur for 4 people. The taxi from Zagreb to Karlovac is about 70 Eur.
b) To Ljubljana airport and take a taxi to Metlika, Slovenia. The cost is about 120 Eur for 4 people.

At both airports (Ljubljana or Zagreb), you also have a rent-a-car option and simply drive to Metlika. From Croatia, the best border crossing is Jurovski Brod near Metlika.

3) Travel by Car

You can drive to Metlika and just use the hotel’s address in Metlika. Parking is available at the hotel or in the town close to the hotel.
Hotel Bela Krajina address: Cesta bratstva in enotnosti 28, 8330 Metlika, Slovenia.
Google Map location


Another great Strel trip! It does not compare to any others and it offers long swims with not having to feel the salt or sea waves! Slovenia is incredible to visit.
~ Mick, UK, August 2022

I very much enjoyed kayaking down the river while swimmers swam. Kolpa is very clean and warm in the summer. Highly recommend visiting.
~ Susan, UK, August 2022

Stunningly beautiful and clean river swimming in the hidden part of Slovenia. Loved it!
~ Suncica, The Netherlands, August 2022

It was great, would do it again for sure! Warm river swimming with small fishes to see along the way.
~ Caroline, Germany, August 2022

Absolute top river swimming trip on the border of Slovenia and Croatia. Clean and pristine river with lovely dams along the way to stop and look around. Beautiful!
~ Guillermo, Spain, August 2021

Price from
30 Jul - 02 Aug, 2024
3 available
590 EUR
20 Aug - 23 Aug, 2024
Trip full