Lincoln Park Zoo, also known as Lincoln Park Zoological Gardens, is a 35-acre zoo in Lincoln Park, Chicago, Illinois. The zoo was founded in 1868 and is the second oldest zoo in the United States. It is also one of a small number of zoos to offer free admission. The zoo is an accredited member of the Association of Zoos and Aquariums. In 2019 it also became an accredited arboretum. Lincoln Park Zoo is home to a wide variety of animals.