The Sigillo Museum is housed on the first floor of the Palazzina delle Arti, above the library of Art and Archeology, and adjacent to the Amedeo Lia Museum. The building dates back to the 1920s and is in the neo-gothic style. The museum houses over 1500 artefacts, ranging from the 4th century to the modern day, and donated to the Comune della Spezia by Lilian and Euro Capellini.
The museum is laid out in chronological and geographical order. Each exhibition displays artefacts recovered from different parts of the world, such as seals in the form of the scarab beetle from Ancient Egypt, rings depicting ancient roman seals dating back to the imperial ages, as well as those dating back to the medieval and renaissance eras. The collection of ecclesiastical signet rings which range in age from the 14th to the 18th century is particularly impressive.