Swietokrzyski National Park was established in 1950 over the area of 6,054 ha. Currently its area amounts to 7,626 ha, out of which 7,212 ha are covered by forests. There are 5 strict nature reserves in the Park.

177 bird species have been observed in vicinity of the Nida river. 143 from among them are hatching there (which is a 1/3 of all Polish bird species). 20 of those species are listed in the “Polish Red Book of Animals”.