Khao Kheow Open Zoo (, , ) is a large zoo in Si Racha, Chonburi, Thailand. It covers an area of about 2,000 acres and contains more than 8,000 animals from more than 300 species. It is the second largest zoo in Asia.
One of the zoo's notable animals is a baby pygmy hippopotamus named Moo Deng.
The Khao Kheow Open Zoo was established in 1974 with an area of about 200 acres in the foothills of Khao Kheow Mountain due to the increasing number of animals in the Dusit Zoo.
In 1978, the zoo was opened to the public. In 1984, the Zoological Park Organization under the Ministry of Natural Resources and Environment allowed an expansion of the area to about 1000 acres. Subsequently, the Thai government decided to expand the area with an additional 800 acres to support education and research about the environment and wildlife. It remains ranked as the second largest zoo in Asia in 2025.
The zoo is famous for offering visitors the chance to see the animals up close, whether by renting a golf cart, driving a car or walking through the exhibits.
In 2021, the zoo came under scrutiny for its elephant swimming exhibit when an Australian photojournalist, Adam Oswell, won the Wildlife Photographer of the Year award for Photojournalism with a photo taken at Khao Kheow. Called "Elephant in the Room," the photo shows an elephant submerged in a tank with a trainer while people watch through an underwater window. The photo's caption says, "Adam uses his photo to draw attention to the crowd watching, rather than the elephant itself, bringing into question these forms of tourist entertainment. Around the world, animals are held captive and deprived of their natural way of life to serve as entertainment in zoos and touring shows." Dr. Visit Arsaithamkul, a veterinarian who worked at Khao Kheow at the time, told CNN that the elephants are trained through "reward-based positive reinforcement" and that "they voluntarily get into the pool.âÂÂ
The zoo will host the mountain biking event during 2025 SEA Games.
The zoo is divided into several thematic zones.
In 2024, a baby pygmy hippopotamus named Moo Deng was born at the zoo. She quickly became an internet phenomenon, boosted the number of visitors to the zoo, and caused the zoo's director to secure copyright and trademark rights for the hippo. Animal rights groups expressed concern for Moo Deng. A spokesperson for People for the Ethical Treatment of Animals (PETA) said, "She faces a lifetime of confinement," while World Animal Protection said, "Sharing Moo Deng content might seem innocuous, but it promotes cruelty to animals.â The zoo's director, Narongwit Chodchoi, rejected the allegations and maintained that the facility ensures the welfare and quality of life for more than 2,000 animals. The Thai Society for the Prevention of Cruelty to Animals, an animal welfare organisation, said that Moo Deng was well taken care of and that PETA was relying on "outdated" information. The pygmy hippopotamus is an endangered species from West Africa, with fewer than 2,000-2,500 adults left, according to the International Union for Conservation of Nature.