"Don't Miss the Gem of Retiro Park No matter what the season, it's worthwhile to wander through the exquisite Retiro Park when you're in Madrid . Here you can find a tranquil escape from crowded streets and museums. The unrivaled architecture of Madrid is echoed here in the wonderful monuments, statues, and buildings. Be sure to visit the gorgeous Crystal Palace (Palacio de Cristal), originally a greenhouse and now used for art exhibitions. Look for the beautiful black swans in the lake."