An aviary is a large enclosure for confining birds, although bats may also be considered for display. Unlike birdcages, aviaries allow birds a larger living space where they can fly; hence, aviaries are also sometimes known as flight cages. Aviaries often contain plants and shrubbery to simulate a natural environment. Various types of aviary Large aviaries are often found in the setting of a zoological garden (for example, the London Zoo, the National Zoo in Washington, D.C., and the San Diego Zoo). Walk-in aviaries also exist in bird parks, including the spacious Jurong BirdPark in Singapore, or the smaller Edward Youde Aviary in Hong Kong. Pittsburgh is home to the USA's National Aviary, perhaps the most prominent example in North America of an aviary not set inside a zoo. However, the oldest public aviary not set inside a zoo in North America, the Hamilton Aviary is located in Hamilton, Ontario, Canada. Tracy Aviary is an example of a bird park within a public urban park, Liberty Park in Salt Lake City, Utah. Some smaller sized aviaries can often be found in European manorial gardens, such as Waddesdon Manor, UK, and Versailles, France. Some public aquaria, such as the Oregon Coast Aquarium, Newport, Oregon, or the Monterey Bay Aquarium, have aquatic aviaries. Home aviaries are popular with some bird fanciers who have the space for them. Many bird breeders list themselves as "aviaries", since most bird pairs breed best in aviaries in contrast to breeding cages. Home aviaries may be built by the owner or obtained from a commercial supplier. There are two main subcategories of home aviaries: grounded aviaries and suspended aviaries. Grounded aviaries are affixed to the ground with a concrete base to prevent rats and other vermin from entering. Suspended aviaries are suspended in the air with only the 'legs' of the aviaries affixed to the ground; hence, the need for a protective base is eliminated in suspended aviaries. Most grounded aviaries typically feature a woodwork or PVC frame unlike the metal frame of public aviaries; however, it isn't uncommon for suspended aviaries to feature a metal frame. Aviaries are also used for research purposes in ornithology institutes. History Early modern origins An aviary, a large cage to house and display birds, dates as far back and possibly earlier than the 1500s found in the Aztec city of Tenochtitlan as noted by Hernán Cortés when he and his