Invernadero del Palacio de Cristal de Arganzuela

This garden is a complete delight: more than 7,000 square metres of plants and vegetation set in what was once a municipal slaughterhouse. It was built between 1908 and 1928 by architect Luis Bellido y González. The restoration was done in the style of 19th-century London or Viennese greenhouses and accommodates 9,000 species of plants, including cacti and succulents, and even some species of fish. Seriously, the place will blow you away.