The Museo Nacional de Artes Decorativas is a hidden gem near the Retiro subway station, dedicated to decorative arts and design. It offers free admission on Saturdays from 2:00 PM to 8:00 PM and on Sundays. The museum's collection includes furniture, ceramics, textiles, glassware, and other decorative objects from different historical periods. Visitors can explore the evolution of design and craftsmanship throughout history and appreciate the beauty and functionality of these exquisite objects.