Buen Retiro Park, formerly the grounds of the palace built for Felipe IV, is Madrid's most popular park and the largest park in central Madrid. Its area is more than 1.4 km² and it is located very close to the Puerta de Alcalá and not far from the Prado Museum. A magnificent park, filled with beautiful sculpture and monuments, galleries, a peaceful lake and host to a variety of events, it is one of Madrid's premier attractions. The park is entirely surrounded by the present-day city. Its lake in the middle once staged mini naval sham battles to amuse royalty; these days the more tranquil pastime of pleasure boating is popular. Inspired by London's crystal palace, the palacio de cristal can be found at the south-eastern end of the park.