It lasted until the end of 17th century, by which time Niebórow was owned by Nieborowski clan of the Prawda (Truth) Coat of Arms.

[5] The estate had its prime with various owners – The Great Hetman of Lithuania Michal Kazimierz Oginski (1766–1774) and Michael Hieronim and Helena of Radziwill clan, who was also the creator of nearby Arkadia.

During their presence in the mansion, its interior has been pompously furnished with rococo and early classicist ornaments designed by Szymon Bogumił Zug.

The straw that broke the camel's back was the squandering of family assets (including Arkadia) by Zygmunt Radziwill, who, in addition, sold the best pieces of art gathered in Nieborów at an auction in Paris.

Prince Michael has proven to be a good landlord – he has restored Nieborów estate to its former glory, and also bought back the Arkadia.

As the Red Army advanced in early 1945, ransacking and seizing the properties of the aristorcatic families, who were seen as the enemies of the working class, the museum's director, Stanisław Lorentz, put up a sign informing that Nieborow was a branch of the state-owned museum and no longer private property of the aristocracy, which saved Nieborow from looting and destruction.

[7] After the war, both the estate and the garden of Arkadia were taken over by the state and became subsidiaries of the National Museum in Warsaw; in 1945, the writer Mieczysław Smolarski was in charge.

Right by the entrance, in the vestibule there are copies of famous sculptures – Head of Niobe and the Roman Bust, as well as the unique theatrical lamp from the 18th century.

[11] The Small Dining Room draws attention with its furniture from the turn of 18th and 19th century, as well as with a series of portraits depicting Polish kings, painted by renowned Polish-Italian painter Marcello Bacciarelli.

Its main feature is a portrait of Anna Orzelska, who was a bastard daughter of king August II and Henryk Renard.

It consists of two big parts: landscape park designed by Tylman van Gameren and rectangular, a French-style garden followed the model of the Versailles.

A special attention must be paid to: marble bas-relief named as “Porwanie Amfitryty przez Posejdona” (Kidnapping of Amphitrite by Poseidon), stone figures called “baby” (the women) which were transported to the park in 19th century from the Black Sea, and an ancient Roman gravestone built by Marek Wincjusz for Acilii Capitolinie.

His wife Helena collected numerous antiquities, ancient sculptures and architectural fragments, Etruscan vases, Roman sarcophagi, funeral urns and medieval artefacts, including the famous Polovtsian cult carvings known as the babas from the twelfth and thirteenth centuries.

[17] In June 1994 the museum received Europejska Nagroda za Ochronę Zabydków (the European Award for Conservation of Monuments) founded by FVS in Hamburg.

Keeping the tradition that dates back to 1944, the Palace offered guest rooms to the most outstanding Polish authors and artists including such names as Andrzej Wajda, Władysław Tatarkiewicz, Aleksander Gieysztor, Maria Dąbrowska and Sławomir Mrożek.