January the 26th, 2026 – The Odra isn’t one that comes up much when Croatia’s rivers are discussed, but this “Amazon river” (as it is often referred to in the local sense), is actually one of Europe’s most important bird habitats.
As Putni kofer/Martina Hrupic writes, whenever the name Odra comes up in conversation, the topic usually heads in two directions (as does the river itself). One goes towards the Czech Republic, where the 845-kilometre-long river bearing that name springs, then through Poland and finally towards the German-Polish border. The other is in Croatia, leading us to Turopolje and the Odra Plain to a much smaller, but equally special river…
the odra – croatia’s “amazon river” in zagreb’s shadow
The Odra, or Croatia’s “Amazon River”, otherwise a left tributary of the Kupa, is a unique river known for the rich fauna that is associated with it and for being one of Europe’s most important bird habitats. It stretches for 45 kilometres (if its course is extended to the Lomnica River, then its final length is as long as 83 kilometres). It is often referred to as a green treasure in Zagreb’s shadow.
Its source is a subject of quite a lot of debate. It was previously believed that its source was actually the Lomnica River, which in turn rises at the foot of Ivanščica. However, more recent data supports the idea that it actually originates from several groundwater sources just north of Velika Gorica. The course of the Odra River is interrupted in one part and joins the Sava-Odra Canal, after which the river flows into the KPD Lake. The Odra then meanders through the untouched forests and plains of Turopolje, all the way to the confluence with the Kupa River.
Consequently, depending on which theory you follow, the length of the river itself changes. This means that there are two currents here too: according to one, it is 45 kilometres long, according to the other, it’s almost twice as long. What’s certain is that, after flowing parallel to the Sava River, it flows into the Kupa River near Sisak.
a haven for animals, plants and birds
The Odra often being called Croatia’s “Amazon River” might sound a bit far-fetched’ at first, but it actually makes a lot of sense. It is long, winding, very wild in places and its banks are rather difficult to access. In addition, many smaller rivers and streams flow into it. As you might expect from such a description, it’s also absolutely teeming with life.
The Odra River is a true paradise for all sorts of animals, from beavers to fish and reptiles, as well as large wild boars, foxes and multiple species of deer. The tiny corn crake nests in the wet meadows of the Odra Plain. This area is one of the most important bird habitats not only in Croatia, but in all of Europe. The white-tailed eagle, on the other hand, lives in the floodplain forests made up primarily of oak.
The left bank of the Odra, Gornja Posavina, is the natural habitat of the original Croatian Posavina horse breed and the Posavina goose. The right bank, Turopolje, has long been occupied by the famous Turopolje pig.
a river that never freezes
As if all this wasn’t enough, the Odra River is interesting for another reason. Despite being very shallow in places, it actually never freezes no matter how cold the temperatures drop. Its maximum depth ranges between five and six metres. The reason it never freezes is the constant flow of water from its deep springs, some of which are in the riverbed itself. For the same reason, its water never warms up above 20 degrees Celsius in the summer, making it an ideal cooling off point.
