Balboa Park is made up of more than 1000 acres and offers fifteen museums, various gardens, arts and international culture associations, as well as the San Diego Zoo, making it a place that offers something historical, horticultural, educational and recreational for everyone. Approximately 14 million visitors come to the park each year. Displays of internationally significant art treasures, exotic animal species, unique model railroads, world folk art, sports memorabilia and rare aircraft–to name a few–are on view in the Park's museums. This urban park, just minutes away from downtown San Diego, is also renowned for its brilliant displays of seasonal flowers, shady groves of trees, and meandering paths through rolling lawns. Balboa Park is managed and maintained by the Developed Regional Parks Division of the City of San Diego Park and Recreation Department. Many of the museums along Balboa Park's Prado are housed in magnificent Spanish Colonial Revival buildings, originally constructed for the 1915–1916 Panama-California Exposition. It was the first time that this richly decorated, highly ornamental architectural style had ever been used in the United States.