The National Zoo and Aquarium (NZA) first opened in 1990 as the National Aquarium. The Aquarium consisted of approximately 30 different species, a large restaurant and function area, with its main feature being a large 1.5 million litre aquarium with an underwater viewing tunnel. This was reportedly the first of its type in the world and was manufactured by a local Canberra company. The Aquarium was situated on around 7 hectares of land which also incorporated a series of outdoor ponds and streams for trout farming. The Aquarium struggled both financially and with some of the major exhibits and within 3 years of opening had been sold to another operator.
This phase of the facility lasted around five years. During this period, the new operator added several outdoor exhibits that consisted mainly of native wildlife. The large aquarium was converted from saltwater to freshwater to reduce costs. The overall theme of the facility changed in an attempt to meet the demands of a large Asian inbound tourist market into the ACT and offered an “Australian” experience that incorporated the wildlife park aspects as well as other activities such as fly fishing in the trout ponds, sheep shearing and boomerang throwing demonstrations.