El Retiro Park, or Parque del Buen Retiro, is a sprawling green oasis covering over 125 hectares in central Madrid. Once a royal retreat, it opened to the public in the late 19th century. The park features the Great Pond, where visitors can rent rowboats, and the stunning Crystal Palace, an exhibition space made of glass and iron. With its manicured gardens, sculptures, and fountains, El Retiro is perfect for leisurely strolls, picnics, and cultural events. On weekends, the park comes alive with street performers, artists, and musicians, offering a lively atmosphere.