The gardens are considered one of the largest and most beautiful roof gardens in Europe. They are spread over an area of 1 ha, where the vegetation covers 5111 m2 and consists of two parts: top (about 2000 m2) and bottom (with an area of 15,000 m2), connected by a stream of cascading water. One can enjoy the panorama of Warsaw from the observation deck. Visitors to the gardens can also look from above into the library through special windows and a glass roof. Admission is free of charge.