See El Retiro's most famous sites including the Crystal Palace, the Philip IV Gate, as well as places that are not listed in guidebooks. El Retiro has more than 19,000 trees of 167 different species, a lake, and a variety of different sculptures, important buildings, and gardens that make the park one of the main attractions in Madrid. Along the way, you'll gain valuable insights from your knowledgeable guide. Then, walk with your guide along the Paseo del Prado until you reach the Prado Museum, which is the main Spanish national art museum. El Prado is widely considered to have one of the world's finest collections of European art, dating from the 12th century to the early 20th century. It's based on the former Spanish Royal Collection, the single best collection of Spanish art in the world. Founded as a museum of painting and sculpture in 1819, it also contains important collections of other types of works. Explore one of the greatest art museums in the world without having to queue. Once you get inside, you'll be able to marvel at the incredible works of Francisco Goya, the most extensively represented artist in the collection, as well as orks by Hieronymus Bosch, El Greco, Peter Paul Rubens, Titian, and Diego Velázquez.