(Polish: Park Mużakowski) is situated on the both sides of Polish-German border represented by the the Lusatian Neisse river (Nysa Łużycka River). Its Polish part is located in in Łęknica town. The nominated core zone covers 348 ha. After the Second World War, the border between Poland and Germany divided the area of the mid 19^th century Muskauer Park in 2 parts - the western side, extends into the German town Bad Muskau and incorporates 136,10 ha (including the castle). The Polish part of the park covers 211,90 ha, and it is mostly located in Łęknica town. The Double Bridge connected the park either side of the river. The buffer protection zone encompasses 1.204,65 ha.

The heart of the park are the partially wooded raised areas on the east bank of the river called The Park on Terraces. On July 2, 2004, the UNESCO inscribed the park on the World Heritage List, as an exemplary example of cross-border cultural collaboration between Poland and Germany. It was inscribed to the list on 2 criteria, for breaking new ground in terms of development towards the ideal man-made landscape, and its influence on the development of landscape architecture as a discipline.

The founder of the park was Prince Hermann von Pückler-Muskau (1785-1871), the author of the influential Hints on Landscape Gardening and the owner of the territory of Muskau county since 1811. After prolonged studies in England, in 1815 he founded the Park. As time went by, he established an international school of landscape management in Bad Muskau and outlined the construction of an extensive landscape park which would envelop the town "in a way not done before on such a grand scale".

The works involved remodelling the Old Castle and construction of a Gothic chapel, an English cottage, several bridges, and an orangery. Pückler reconstructed the New Castle as the compositional centre of the park, with a network of paths radiating from it. This went on until 1845, when Pückler was constrained to sell the patrimony. Soon it was bought by Prince Frederik of the Netherlands, who employed Eduard Petzold, Pückler's disciple and a well-known landscape gardener, to complete his design.

During the Battle of Berlin, both castles were levelled and all 4 bridges across the Neisse were razed. Since 1945 the park has been divided by the state border between Poland and Germany, with two thirds of it on the Polish side. The Old Castle was rebuilt by the East German administration in 1965-72, while the New Castle and the bridges are still being restored.