La Specola, one of the oldest science museums in Europe, contains a collection of specimens of the natural world—some of which date back to the 16th century. It includes strange and wonderful objects ranging from tiny iridescent green beetles and multicolored butterflies to whale and rhinoceros skeletons. There's even a hippo, preserved by taxidermy, that was once pet to the Medici family and lived in the Boboli Gardens! The extraordinary, if slightly creepy, anatomical waxes filling the last four rooms of the museum were once used to train Florentine medical students. The frescoes and elaborate pietra dura inlays that decorate the walls and ceilings detail Italian scientific achievements.