Museo Galileo, the former Istituto e Museo di Storia della Scienza (Institute and Museum of the History of Science) is located in Florence, Italy, in Piazza dei Giudici, along the River Arno and close to the Uffizi Gallery. It is housed in Palazzo Castellani, an 11th-century building which was then known as the Castello d’Altafronte. Museo Galileo owns one of the world’s major collection of scientific instruments, which bears evidence of the crucial role that the Medici and Lorraine Grand Dukes attached to science and scientists. The Museo di Storia della Scienza re-opened to the public under the new name Museo Galileo on June 10, 2010, after a two-year closure due to important redesigning and renovation works. It was inaugurated just four hundred years after the publication in March 1610 of Galileo’s Sidereus Nuncius (The Starry Messenger), the booklet that revolutionized mankind’s conception of the universe, decisively contributing to the advent of modern science.