In April 1940, a young Princess Elizabeth visited the aviary in the grounds of the Royal Lodge, Windsor, with her mother Queen Elizabeth and younger sister Princess Margaret.
The royal family enjoyed a visit to London Zoo in May 1939, where a 13-year-old Princess Elizabeth reached out to a chimpanzee while her sister Princess Margaret looked on.
Princesses Elizabeth and Margaret also got to meet a panda during their day trip to the zoo.
The royals often visited London Zoo together, and were accompanied by their nanny Miss Crawford to see the wildlife in 1938.
On the same trip the young Princesses Elizabeth and Margaret were photographed with the penguins as they toured London Zoo.
The Queen enjoyed regular visits to the zoo as a child, and is pictured here with a chimpanzee in the early 1930s.
Queen Elizabeth ll and Prince Philip, Duke of Edinburgh watch sea lions being fed during a visit to the Institute of Oceanography in February 1983 in San Diego, California.
King George VI joined his daughters Princess Elizabeth and Princess Margaret for photos next to an aviary in the gardens of Windsor Castle in July 1946.
Queen Elizabeth came face to face with koalas during a visit to a wildlife park in Brisbane during her official tour of Australia in October 2011.
The Queen was joined by Prince Philip to officially open the new Land of the Lions exhibit at ZSL London Zoo on Thursday - the zoo she so often enjoyed to visit as a child.