Inside the convent adjoining Chiesa di Sant'Agostino, this small museum explores the evolution of modern sculpture through 700-odd bozzetti (maquettes or models) and plaster moulds of famous sculptures cast or carved in Pietrasanta by some 350 artists from all over the world since the early 20th century.
Don't leave without enquiring about the latest additions to the museum's informal Parco della Scultura (Sculpture Park), an open-air trail leading to 70 public works of art in and around town. Check the museum's website for a complete list of artworks.