This nature reserve and the region are named after the small river of Lonjsko which floods the land when in spate (6 months a year). At that time, the marshes attract numerous migratory birds (nearly 239 species). However, the appeal of Lonjsko Polje lies not only in its fauna and landscapes; the surrounding villages, built below the sea wall, have retained their traditions, symbolised by the lovely wooden houses, while in the meadows, the local race of Posavina horses can be seen grazing.