In the south of Herzegovina, in a typical karst environment, on the left side of the Neretva River, there is the Hutovo Blato Nature Park, a unique sub-Mediterranean wetland in Europe. It has been known since ancient times as a green oasis, with an abundance of water in which a large number of plant and animal species have found living conditions. The wetland is interesting and significant from an ornithological, ichthyological, scientific, ecological and tourist point of view. Hutovo blato is considered to be one of the largest wintering grounds for birds in Europe. Hutovo blato territorially belongs to the municipalities of Čapljina and Stolac, and spreads over wetlands, plains and hilly terrain, with an altitude of 1 m to 432 m.
This area is about fifteen kilometers from the Adriatic Sea, so it is heavily influenced by the Mediterranean climate. Due to its exceptional importance and beauty, Hutovo blato has been declared a Nature Park in 1995. Merging into valleys and depressions, karst sinkholes and surface waters from the surrounding areas create a larger number of lakes, ravines, molds and the Krupa River and provide high groundwater levels. Such a high groundwater level affects the occurrence of permanent and intermittent springs and wells.
Lakes Hutova blata are real crypto-depressions, because the bottoms of some lakes are below sea level (Jelim 18 m). The largest lakes of Hutova blata are: Deransko, Jelim, Drijen, Orah, Škrka and Svitava. Lake Svitavsko is an artificial accumulation, created by the construction of the hydroelectric power plant Čapljina. All lakes of Hutova blata are interconnected by a large number of canals and ravines.
The Krupa River is the main watercourse of Hutova Blata and drains the waters of Gornji Blato and Svitavsko Lake into the Neretva River. Krupa has no real source but the island of Lake Deran. The length of Krupa is 9 km, and its average depth is about 5 meters. This is a unique river in Europe because it has the property of flowing in both directions. It flows normally from the "source" to the estuary, and from the estuary to the "source". This phenomenon occurs when due to high levels and high water flow, the river Neretva pushes Krupa.
Thanks to the proximity and influence of the Adriatic Sea, the abundance of water surrounded by karst-hilly terrain, the biological diversity of Hutova blata vegetation is extremely valuable. Few places in the world have such a large number of species in such a small area. The entire vegetation cover of the Nature Park can be divided into four types of vegetation: aquatic, wetland, meadow and forest. The water surfaces of the Hut mud are mostly covered with water lily (Nymphaea alba) and water lily (Nuphar luteum). In addition, Potamogeton (Potamogeton sp.), Frogweed (Ranunculus sp.), Etc. are represented in the vegetation of water surfaces. ), sedges (Carex sp.) and sieves (Juncus sp.).
Forest and meadow vegetation are represented by numerous characteristic species that complement the biological diversity of Hut mud. Significant species of these types of vegetation are: ash (Fraxinus sp.), Oak (Quercus sp.), Boar (Ruscus sp.), Pomegranate (Punica sp.), Pine (Juniperus sp.), Willow (Salix sp.), Elm (Ulmus sp.), Alder (Alnus sp.), Blackberry (Rubus sp.), Mulberry (Morus sp.), Nettle (Lamium sp.), Clover (Trifolium sp.). Some plant communities are only developed in places, while some are very widespread and cover large areas.