Duration: 3 days
Pace: Balanced
Car-free: Mixed
Family friendly: Yes
Season: May to October
Budget: €70 to €120 per day, indicative
Travellers who want a compact north-west loop: big water on fenced decks, a ridge castle over a green river, a riverside fortress in the city, and shaded footbridges at Krupa na Vrbasu.
Bihać base for Una → Banja Luka base for riverside and Krupa → Kozara option → onward or return.
~6 to 9 hours across three days, spread over one intercity transfer and short local hops.
On foot at decks and bridges; guided transfers or self-drive between bases; car-free works with a prebooked Una day and a local transfer to Krupa.
Day
Travel time in park Bihać to Štrbački Buk about 50 to 70 minutes; Bihać to Martin Brod about 50 to 70 minutes
Walk the signed platforms at Štrbački Buk, then the shaded wooden bridges and channels at Martin Brod. On the way back, stop at Ostrožac Castle for long looks over the Una bends.
Use rails on decks and bridges. Take shaded breaks in summer.
Boards and stones can be wet; shoes with grip help.
Bihać.
Day
Bihać to Banja Luka about 2.5 to 3 hours
Arrive in Banja Luka and walk Kastel Fortress above the Vrbas. Follow the riverside for low, level frames and a quiet café stop. Keep the evening easy in the centre.
Wide pavements and level paths suit mixed ages.
Kastel has low edges; keep well inside parapets.
Banja Luka.
Day
Banja Luka to Krupa na Vrbasu about 25 to 40 minutes; Banja Luka to Kozara National Park about 1 to 1.5 hours
Short spans and shaded channels at Krupa na Vrbasu make an easy morning. If you have extra time, add a Kozara National Park terrace and a short forest loop before you continue.
Rails are low at Krupa; supervise children near water.
Uneven planks in places; take care on narrow bridges.
Depart or add a Banja Luka night if you insert Kozara.
Mountain and valley speeds are modest. Allow buffer time for the Bihać to Banja Luka leg. Guided transfers reduce fatigue on park days.
Una park gates and car parks use small fees; carry some cash for gates and cafés.
May to October suits decks, bridges and forest shade. Spring flows are stronger; late summer water is calmer for soft-rafting add-ons.
Base in Bihać for a shared Una day, then take a regional bus to Banja Luka and a short prebooked transfer to Krupa.
Closed shoes with grip, sun cover, water, and light layers.
Stay behind rails at decks, keep back from edges at castles, never swim near falls, and follow posted rules. Drones are restricted in parks and river corridors.
Replace part of Day 1 afternoon with a family soft run near Lohovo with licensed guides.
One Bihać day for decks and bridges, then a direct run to Banja Luka with a short Kastel loop before onward travel.
Add a full Kozara day and a second river morning in Banja Luka.
Bihać to Štrbački Buk about 50 to 70 minutes, to Martin Brod about 50 to 70 minutes, Bihać–Banja Luka about 2.5 to 3 hours, Banja Luka–Krupa about 25 to 40 minutes.
Yes with a shared Una day, a regional bus to Banja Luka, and a short prebooked transfer to Krupa.
Yes with supervision. Keep to fenced decks and bridges and inside parapets at Kastel and Ostrožac.
May to October for long light and calm river time. Spring has stronger flows; winter works with shorter outdoor blocks.
Yes on calm sections near Lohovo in season. Book with licensed guides and follow age and height limits.
