The stunning, late-17th-century Nieborów Palace is a classic example of baroque architecture. It was designed by Tylman van Gameren for Cardinal Radziejowski, the archbishop of Gniezno and primate of Poland. In 1774 Prince Michał Hieronim Radziwiłł bought the palace, and he and his wife Helena set about cramming it with as much furniture and works of art as they possibly could. More than half of the palace rooms are devoted to the Nieborów Museum.
Part of the ground floor features 1st-century Roman sculpture and bas-reliefs collected by Helena, and highly unusual black-oak panelling from the late 19th century. The stairwell leading to the 1st floor, with its ornamental Dutch tiles dating from around 1700, is worth the entry fee alone. The grounds around the palace, which thankfully has not been over-restored, are serene and worth a wander.
Nieborów is on the Łowicz–Skierniewice road, Hwy 70, and is reachable by bus from Łowicz. You can also hike or bike along a specially marked cycling path, known as the 'Prince Bike Trail' (Szlak Książęcy). The blue-marked path runs about 14km and starts at the Stary Rynek in Łowicz, near the entrance to the museum.