From Wikipedia (The text is somewhat clumsily translated from Italian into German, but perhaps still a reference point for those interested):
The Sinopie frescoes of the monumental cemetery are kept in the Sinopie Museum in Piazza del Duomo in Pisa.
The frescoes, works of various artists including Buffalmacco, Andrea Bonaiuti, Antonio Veneziano, Spinello Aretino, Taddeo Gaddi, Piero di Puccio, Benozzo Gozzoli and others, once covered the walls of the cemetery and were destroyed or in any case badly damaged in the fire in the year 1944 due to an Allied bombing raid.
On this occasion the frescoes were removed for the very urgent restoration (most of them still in progress) and it was found that these preparatory drawings were exceptionally well preserved. After the restoration, they were housed in the current museum, located on the south side of Piazza del Duomo, where one of the two ticket offices of the monumental complex is located.
In the museum, in addition to the Sinopias themselves, there are two multimedia areas: one in which a stereoscopic 3D simulation of the monumental cemetery is reproduced over the centuries, and the other in which audiovisual material about the cemetery is shown in a kind of mini-cinema Structural projection and the restoration work on the leaning tower, initially only in English.