Plizio Visual Lab

Gromiželj Special Nature Reserve

Plizio editorial teamUpdated: Jun 2026Data Sources

wildlife

Weather…

The Gromiželj Special Nature Reserve is located near Bijeljina in northeastern Bosnia and Herzegovina, encompassing one of the last remaining marsh and peatland areas in the Semberija region. The reserve gained international scientific fame in 2008 following the discovery of the European mudminnow (Umbra krameri), an extremely rare fish species and a relict from the Ice Age. Covering an area of approximately 830 hectares, the reserve forms a complex ecosystem consisting of ponds, reed beds, and wet meadows. This landscape provides a sanctuary for over 400 plant species and numerous protected animal species, including rare amphibians and migratory birds. The geological structure of the soil allows for effective water retention even during extended dry spells, ensuring the ecological stability of the entire area. Gromiželj serves not only as a site for intensive scientific research but also as an educational center for nature conservation within the Western Balkans. Preserving this fragile wetland is critical for maintaining regional biodiversity and mitigating the impacts of climate change on the edge of the Pannonian Basin.

Location: Bosnia and Herzegovina
Nearby: Bijeljina (14 km)

Best time to visit & climate

The most pleasant time to visit is Jun, Aug, Sep.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg °C	0	2	7	12	17	22	24	24	18	13	7	1
Rain mm	50	51	54	55	89	88	63	59	63	59	52	52

📋 Practical info

📅

Best season

The best time to observe the European mudminnow (Umbra krameri) is in spring and early summer when water temperatures rise. From April to June the fish spawn and are most active in shallow ponds.

🌅

Best time of day

Early morning the fish are often visible in sunlit shallow water zones. Late afternoon activity decreases, but aquatic plants then provide good habitat for insects.

📜

Etiquette

Do not enter the ponds and wetlands to protect the rare fish habitat. Fishing is strictly prohibited and any disturbance of the waters must be avoided.

🎒

What to bring

Rubber boots are necessary to walk the wet trails along the ponds. Binoculars can be useful for watching birds that feed on the insects.

🧭

Getting there

The Gromiželj Reserve is located near Brčko in northern Bosnia. It is reachable via local roads, but roads are often unpaved; a 4x4 is recommended.

🦌

What to expect

The rare European mudminnow is hard to see as it camouflages well. Patience and quiet behavior near the water increase chances of glimpsing this shy species.

Geography

Coordinates

44.85170, 19.33750

Facts

The European mudminnow (Umbra krameri) was officially discovered in Gromiželj in 2008.
The reserve covers a total protected area of 831.33 hectares.
Scientific surveys have documented over 400 different plant species within the reserve.
Gromiželj is the only confirmed habitat for Umbra krameri in Bosnia and Herzegovina.
The site is located within the Bijeljina municipality, specifically near the village of Velino Selo.
It was designated a Special Nature Reserve to safeguard its unique Ice Age ecological features.

Explore nearby

Notable places around

Ethno Village Stanišići9 km · SWExplore →

Bijeljina14 km · SWExplore →

Zasavica Wetlands20 km · NEExplore →

Janja22 km · SExplore →

Sava25 km · EExplore →

Srem Museum Sremska Mitrovica25 km · NEExplore →

Sabac Industrial Zone29 km · EExplore →

Privina Glava Monastery31 km · NExplore →

Route planner — Car & Motorhome

Where do you start? We build the route here, with stops and country notes along the way.

Start Destination Via (optional)

Overnight stops

Vehicle

Only stops with (optional): 💧 Water ♻️ Disposal 🔌 Power 🚻 Toilets 🚿 Shower

Sights in the town Gromiželj Special Nature Reserve (1)

Balatun📍 landmark

Balatun is a wetland area in the Gromiželj reserve, home to water birds.

Sights nearby

Frequently asked questions

What makes the Gromiželj reserve so special?

It is home to the rare European mudminnow (Umbra krameri).

Where exactly is Gromiželj located?

It is located near Bijeljina in the Semberija region, in the northeast of the country.

What type of ecosystem is found here?

A marshland with 'floating islands' and a specific bog history.

Is the area developed for tourists?

It is primarily a scientific reserve; visits should be coordinated with local experts.

Are there rare plants there?

Yes, besides the fauna, numerous rare wetland plants can be discovered.

Gromiželj Special Nature Reserve: where is it located?

Gromiželj Special Nature Reserve is located in Bosnia and Herzegovina.

Gromiželj Special Nature Reserve: when is the best time to visit?