Sibyl Temple was built between 1798 and 1801, according to the Project of Ch.P.Aigner, ancient Temple of Vesta in Tivoli, near Rome. The building in the rotunda shape, surrounded by Corinthian columns, consists of two circular rooms: the entrance to the upper is guarded by two ancient sphinxes. It was the first museum in Poland Izabella Czartoryska gathered here memorabilia related to the history of Poland, knightly exhibits and military. Much space is devoted to Zamoyski,, Chodkiewicz, Czarniecki, Kościuszko. Lower hall was dedicated to priest Józef Poniatowski.