In the years 1690-1696, on the initiative of Primate Michał Stefan Radziejowski, a Baroque palace was erected according to a design by Tylman of Gameren. At the end of the 18th century the estate got into the hands of Prince Michał hieronim Radzwiłł and his wife Helena nee Przeüdziecka. They richly furnished it and partly changed the interior decorations. They also brought with them many valuable works of art, including the head sculpure of "Niobe", a Roman copy of the Greek original from the 4th century. Not far from Nieborów a sentimental park called Arkadia was soon founded by Princess Helena Radzwiłł; one of the designers was Szymon Bogumił Zug. The last owner of Nieborów was Prince Janusz Radzwiłł who modernized the palace in 1922 according to a design by Romuald Gutt. After 1945 Nieborów became a branch of the Warsaw National Museum. Apart from the magnificent interior the palace has a rich library, guest-rooms, and it hosts various meetings and conferences. it is surrounded by an enchanting and well-kept park.