3.ST12.001 is a large nature reserve part of Roztocze located in the southeastern corner of Poland, at the foot of the Vistula river. It has been designated as the first of its kind in the region due to its distinctive and rare natural heritage, containing some of the most valuable forests and wetlands in the country. It consists of various habitats, including old-growth and secondary forests, wetlands and meadows, with a great variety of flora and fauna. It is an area that has remained largely untouched by human activity and is home to numerous rare and protected plant and animal species, such as black storks, beavers, otters, marsh harriers and European bats, as well as numerous other species of protected birds, plants and mammals.