The second museum building rebuilt from the former baroque pavilion according to the design of the architect Christian Peter Aigner. It was opened in 1809 on the occasion of the visit of Polish troops by Prince Józef Poniatowski in Puławy. Princess Czartoryska gathered a rich collection of foreign memorabilia, sent and brought back from numerous travels across Europe (artistic crafts, militaria, and painting). The Gothic House also housed Polish collections, as without them, the building seemed empty and insignificant to Princess Czartoryska.
Exhibited here were, among others: Lady with an Ermine by Leonardo da Vinci, Landscape with the Good Samaritan by Rembrandt van Rijn, and the Portrait of a Young Man by Raphael Santi. Among the fairly diverse exhibition, there were also items of a purely sentimental nature, such as: Shakespeare's chair, a dry biscuit of Napoleon Bonaparte, a tin with relics of Abelard and Heloise, or stones from the grave of Romeo and Juliet. A cup of Kara Mustafa, James Cook's sword, manuscripts, and literary works were also stored here.
The building was designed so that the exhibition was placed not only inside but also outside. Thus, in the nine walls of the building, which have their respective names (Długosza, Kazimierza Wielkiego, Litewska, Żółkiewskiego, Boguty and Sędziwoja, Rzymska, Gostyńska, Kościuszki, Cyda and Chimeny), lapidaria brought from various corners of Poland and Europe were embedded. Among them were, among others, balls from battlefields, reliefs, fragments of fortified strongholds, vases. On one of the walls, there was also a foundation plaque: Elżbieta Czartoryska MDCCCIX, and in the wall of Kazimierz Wielkiego, a saying taken from Virgil's Aeneid defining the idea of collecting memorabilia was embedded: I pamiątki łzy wyciskają i znikome rzeczy duszę rozczulają.
The main core of the Gothic House consists of an oval hall on the first and second floors. The ground floor consists of a hallway and a room called the Room under the Coat of Arms. Once, its walls were adorned with coats of arms of prominent Polish families. The winding staircase leads to the first floor. Its decoration is the Green Room, named after the upholstery of the walls. It is adorned with stylized stucco friezes; worthy of attention is the inlaid floor and a copy of the fireplace from the Marynka palace (the original was lost during World War II). The decorative balustrade connecting two Corinthian columns also presents beautifully. At the back is the so-called Raspberry Room known as the study, where the princess worked on the collections.
