The Museo Nacional de Ciencias Naturales is a fascinating natural history museum near the Retiro subway station. It offers free admission on Saturdays from 5:00 PM to 8:00 PM and on Sundays. The museum's collection includes a wide range of specimens, fossils, and interactive exhibits that showcase the diversity of life on Earth. Visitors can learn about the evolution of species, explore ecosystems, and discover the wonders of the natural world through engaging displays and educational programs.