Melbourne Zoo's gorilla enclosure turns 25

The gorilla enclosure at Melbourne Zoo is celebrating a milestone birthday.

Melbourne Zoo's new Gorilla Otana turns 13 and was given a frozen treat to celebrate the day. Tuesday, Jan. 28, 2014.

The gorilla enclosure at Melbourne Zoo is turning 25 years old.

A male gorilla (back) confronts a female gorilla at the Melbuorne Zoo in Melbourne, Wednesday, Oct. 6, 2010.

The "Gorilla Rainforest" opened on April 11, 1990, and is now home to an established family group.

Six gorilla babies have been conceived and born in the 1600-square-metre enclosure, which is planted to resemble African rainforest.

A supplied image obtained Sunday, March 15, 2015 shows the newly born Western Lowland Gorilla born in Melbourne Zoo.