The Smithsonian Institute for Conservation Biology (SCBI) is part of the Smithsonian. It is located near Front Royal, Virginia and has a 3,200-acre (13 km2) campus. This includes the Smithsonian National Zoo. The total area of the Smithsonian Conservation Biology Institute is considered the largest zoo in the world by area.

The Smithsonian National Zoo is one of the oldest zoos in the United States with 400 species of animals. It is part of the Smithsonian Institution and requires no admission fee. The main exhibits are the Amazon, the Asian Trail, the Giant Panda Habitat, the Great Ape House, and the Think Tank.

Total Land Area: 3,200 acres (13 km2)

Area of The Smithsonian National Zoo: 163 acres

Location: Smithsonian’s National Zoo & Conservation Biology Institute 3001 Connecticut Ave., NW Washington, DC 20008, U.S.

No. of Animals: 2,000

No. of species‎: ‎400
Date opened‎: ‎May 6, 1889

Website; http://nationalzoo.si.edu/scbi/default.cfm

Living Desert Zoo and Gardens is formerly called the "Living Desert Museum". A desert botanical garden and zoo located in Palm Desert, Riverside County, California, United States. The Living Desert Zoo includes the Sonoran Desert in the Coachella Valley and the foothills of the Santa Rosa Mountains near Palm Springs, California.

Desert Zoo and Gardens has been a member of the Zoo and Aquarium Association (AZA) since 1983 and a member of the World Zoo and Aquarium Association (WAZA). He has been involved in species reintroduction programs, including the return of local mountain peninsula bighorn sheep and Arabian oryx to Oman.

Area: 1,800 acres (730 ha)

Location: Palm Desert, California, United States

Timing: Open 8:00am to 5:00pm

No. of animals: 430

No. of species: 150

Date opened‎: March 1970

Annual visitors: over 500,000

Website: www.livingdesert.org

In 2010, The San Diego Zoo Safari Park was renamed as San Diego Wild Animal Park, situated in the San Pasqual Valley area of San Diego, California, near Escondido with a total area of 1,800 acres (730 ha).

The San Diego Zoo Safari Park is one of the largest tourist attractions in San Diego Country. The park has a large number of wild and endangered animals that include species from the continents of Africa, Asia, Europe, North and South America, and Australia. San Diego Zoo is part of this Safari Park. We included the total area of San Diego Zoo and Safari park in this list of the largest zoos in the world. The park, visited by 2 million people annually, houses over 2,600 animals representing more than 300 species, as well as 3,500 plant species.

Total Land Area: 1,800 acres (7.3 km2)

LocationCity of San Diego

Timing: 9 a.m. to 5 p.m.

No. of animals: 3500+

No. of species: 400+

Date opened: May 10, 1972

Annual visitors‎: 2 million people

Website: www.sdzsafaripark.org

The North Carolina Zoo is a zoo in Asheboro, North Carolina, housing 1,800 animals of more than 250 species, primarily representing Africa and North America. It has a total area of 2,600 acres (1,100 ha) in which 500 acres (200 ha) is a developed area. It is the world`s largest natural habitat zoo in the world and one of two state-supported zoos.

The North Carolina Zoo is a part of the North Carolina Department of Natural and Cultural Resources. The zoo is open 363 days a year (closed on Thanksgiving and Christmas) and receives more than 900,000 visitors annually.

Land area: 2,600 acres (1,100 ha)

Address: Asheboro, North Carolina, United States

Timing: 9 a.m. – 4 p.m.

No. of animals: 1,800

No. of species: 250

Date opened: August 13, 1974

Annual visitors: 860,000

Website: https://www.nczoo.org/

The Miami Zoo, also known as the Miami-Dade Zoological Park and Gardens, is the largest zoo in the United States and the largest zoo in North America. The Miami Zoo has approximately 750 acres (304 ha) of macaws, of which only 324 acres (131 ha) are kept. This zoo has over 3000 animals.

Zoo Miami opened as Crandon Park Zoo in 1948 and moved to Metro Miami on July 4, 1980, to the former location of the Richmond Naval Air Station,[3] southwest of Miami in southern metropolitan Miami-Dade County, in the center of the census-designated places of Three Lakes (north), South Miami Heights (south), Palmetto Estates (east) and Richmond West (west).

Area: 750 acres (304 ha) (324 acres (131 ha) developed
Location: Miami-Dade County, Florida, United States
Timings: 10:00 AM – 5:00 PM
No. of animals: 3000
No. of species: 500
Date Opened: 1948 as Crandon Park Zoo | July 4, 1980, as Miami MetroZoo

Website: www.zoomiami.org

Dubbed America's premier zoo, Columbus Zoo offers a variety of attractions to offer visitors an unforgettable experience. It covers approximately 580 acres and is home to approximately 7000 animal species, representing over 800 species, and welcomes over 2.3 million visitors annually.

In addition to this, Columbus Zoo runs its own conservation programs, donating funds to third-party programs and participating in their own conservation efforts. Over the past five years, the zoo has invested more than $3.3 million in more than 70 projects in 30 countries.

Area: 580 acres
Location: 4850 W Powell Rd, Powell, OH 43065, USA
Timings: 09:00 AM to 05:00 PM
Date opened‎: ‎1927
No. of species‎: ‎over 800
No. of Animals: more than 7,000
Annual Visitors: 2.3 million

Website: www.columbuszoo.org

The Bronx Zoo is one of the oldest metropolitan zoos in the world. Located in the majestic city of New York, it covers approximately 265 acres and is home to approximately 4,000 animals of various species. It is also one of New York's top attractions, with nearly two million visitors each year.

In fact, The Bronx Zoo is a must-see for all animal lovers in gorgeous New York City. The Bronx Zoo is also world-renowned for its large and diverse animal collections and award-winning exhibits. The zoo is part of an integrated system of four zoos and one aquarium managed by the Wildlife Conservation Society (WCS) and accredited by the Zoo and Aquarium Association (AZA).

Area: 265 acre
Location: 2300 Southern Blvd, Bronx, NY 10460, USA
Timings: 10:00 AM to 05:00 PM (Mon-Fri); 10:00 AM to 05:30 PM (Sat, Sun)
Date opened: November 8, 1899
No. of animals‎: ‎4,000 (2010)
No. of species‎: ‎650 (2010)

Annual Visitors: 2.15 million

Website: www.bronxzoo.com

One of the world's most expensive attractions, the Henry Doorley Zoo and Aquarium is located in Omaha, Nebraska. With over 17,000 animals from 962 species, the Omaha Zoo spans 130 acres. It is also home to the largest feline complex in North America, the largest covered swamp in the world, the largest covered desert in the world, and one of the state's most popular tourist attractions, with the largest glazed geodesic dome in the world. ...

Omaha's Henry Doorly Zoo and Aquarium is nationally renowned for its leadership in animal conservation and research. Evolving from the public Riverview Park Zoo established in 1894, today the zoo includes several notable exhibits.

Area: 130 acres
Location: 3701 S 10th St, Omaha, NE 68107, USA
Timings: 09:00 AM to 05:00 PM

Date opened: 1894 as Riverview Park Zoo
No. of Species: 962
Annual visitors: ~2,000,000

Website: www.omahazoo.com

Brookfield Zoo, also known as Chicago Zoological Park, is a zoo located in the Chicago suburbs of Brookfield, Illinois. About 450 species of animals live on 216 acres (87 hectares). It opened on July 1, 1934, and quickly gained international recognition for its use of ditches and ditches instead of cages to separate visitors from other animals and animals.

Brookfield Zoo is also home to the first exhibit of giant pandas in the United States. One of the giant pandas (Su Lin) was stuffed and displayed at the Chicago Museum of Natural History. In 1960, Brookfield Zoo built the country's first fully enclosed dolphin exhibit, and in the 1980s, the zoo introduced Tropical World, the first fully enclosed rainforest simulation and the world's largest indoor zoo at the time.

Land area: 216 acres (87 ha)

Location: Brookfield, Illinois, United States

No. of animals:2300
No. of species:450

Date opened: July 1, 1934

Annual Visitors: 2.2 million

Website: www.brookfieldzoo.org

Located in the Philadelphia Centennial District on the western bank of the Schuylkill River, the Philadelphia Zoo was America's first true zoo. It was registered with the Commonwealth of Pennsylvania on March 21, 1859, but its opening was delayed until July 1, 1874 due to the Civil War.

Philadelphia Zoo is open with 1000 animals and an entrance fee of 25 cents. They also housed animals from safaris on behalf of the Smithsonian Society, which has not yet built a national zoo. The zoo covers 42 acres (17 hectares) and is home to nearly 1,300 animals, many of which are rare and endangered. The hotel features a zoo, catamaran lakes, rainforest-themed carousels, rope courses, and a variety of interactive and educational exhibits.

Land area: 42 acres (17 ha)

Location: Philadelphia, Pennsylvania, US

No. of animals:~1,300
No. of species: 340+

Annual visitors: 1.2 million

Date opened: July 1, 1874

Website: https://philadelphiazoo.org/