Dusit Zoo was originally a botanical garden called “Khao Din Wana”. King Rama V, during his foreign country visits became impressed of botanical gardens as a place for entertainment and relaxation of people. So, in 1895 the king gave permission for the botanical garden to be built within Suan Dusit garden on land east of Premprachakorn canal, across from Chitralada Palace. A large lake was dug up with connecting canals and roads. The shape of the lake when seen from above resembles the Thai initials of King Rama V. Dirt excavated from the digging was piled into a mountain in the middle of the garden, hence the name “Khao Din” which means earth mountain. Various trees were planted and called “Wana” which means forest. And so the whole area was called “Khao Din Wana”. At first the garden was part of the palace compound and used for the private enjoyment of the royal family and palace staff.
When King Rama V traveled to the Java Islands in 1908, he brought back several chital deer to Bangkok and raised them in the garden located in Ambara Villa, Dusit Palace. Afterwards, the descendants of these chital deer were moved to Dusit Zoo. Later, King Rama VII advised that this garden should be expanded and improved for the enjoyment of the general public and also commanded to construct the Parti-coloured Glasshouse (Ruen Krajok Larski) which today still can be seen in Dusit Zoo.
After the revolution when Thailand changed from an absolute into a constitutional monarchy in 1932, Prime Minister P. Piboonsongkram asked the King’s permission to turn the Dusit Botanical Garden into a public zoo, to be administered by the Bangkok Municipality. In 1938 a law was passed that designated the areas of “Khao Din Wana”, “Sanam Sua Pa” and “Suan Umporn” as a zoo and a public park.
Meanwhile the Bangkok Municipality had constructed the zoological park and moved the chital deer from Ambara Villa, Dusit Palace, Axis deer and various animals from Suan Umpron, and crocodiles and monkeys from Suan Saranrom to the zoo. A request was also made for royal elephants from the palace to be shown at the zoo on sundays. After all the renovations were finished, the zoo opened its gates to the public on 18 March 1938 and from then on was officially called Dusit Zoo.
During the World War II allied attacks by aeroplanes, the Thai Ministry of Defence introduced measures to prevent aerial incidents, to prepare the people for emergencies during the war. Those measures encouraged people to construct air-raid shelters in many public places to prevent accidents during the allied bombing. At that time Dusit Zoo was a zoo as well as a public park, so an air-raid shelter was built in the park. After the war ended, the air-raid shelter was renovated by building a model mountain over it for keeping the Sumatran serow. As well as this shelter, the air-raid shelters in other public places including the shelter at Hualumpong, beneath the Charoenpas bridge, above the Parusakawan palace, and in the Rajabhat institute Suansunanta campus were all renovated and adjusted for other uses. Only a few remained to be seen.
When after more than 10 years the Bangkok Municipality was not able to sustain and operate Dusit Zoo any longer due to financial issues, it was proposed to the government to establish a governmental zoological administrative organisation. On 15 February 1954, a Royal Decree was issued to set up this Zoological Park Organisation of Thailand (ZPO), a governmental agency responsible for taking care of zoos. It operated under the responsibility of the Office of the Prime Minister and on 1 July the Bangkok Municipality submitted all the zoological work and properties to ZPO. Currently, ZPO is the non-profit state enterprise under the responsibility of Ministry of Natural Resources which has five zoos under its responsibilities comprising Dusit Zoo, Chiang Mai Zoo, Kao Kheow Open Zoo, Nakhon Ratchasima Zoo, and Song Kla Zoo. ZPO headquarters is located within Dusit Zoo on Rama V road opposite to the Chitrlada Palace, and is responsible for the breeding activities in its facilities and conservational efforts, as well as providing education and recreation.
(Sources: ZPO website; information panels in Dusit Zoo)