Museo Galileo is located in Piazza dei Giudici, in the premises of Palazzo Castellani, a building of ancient origins known in Dante’s time as Castello d’Altafronte. It houses one of the most significant collections of scientific instruments in the world, a material testimony to the importance attributed to science and its protagonists by the members of the Medici dynasty and their successors, the Lorraine Grand Dukes. Among the most valuable pieces preserved in the museum’s halls, we can mention the telescope used by Galileo to observe the Moon and the satellites of Jupiter, and the monumental armillary sphere created between 1588 and 1593 by Antonio Santucci at the behest of Ferdinando I de’ Medici.