The Blue Planet, National Aquarium Denmark, Kastrup, Denmark

Denmark's Aquarium in Charlottenlund started construction in 1937 and was opened in 1939. In 1974, this aquarium was expanded to feature five large landscape aquaria and a biological museum with theme-based exhibits and aquariums. In 1990, the facility was further expanded by a new front hall, café, improved toilet facilities and a schooler service. In the final years before the closure of the aquarium in Charlottenlund, it had about 1,000,000 litres (220,000 imp gal; 260,000 US gal) of water in about 70 aquarium tanks.
New aquarium
The Blue Planet opened in 2013 in Kastrup, a suburb of Copenhagen. It resembles a whirlpool when seen from above. It often is, being close to the Copenhagen Airport. It was designed by Danish architects 3XN. To reduce energy consumption the building is equipped with cooling units using seawater from Øresund and double glazing. It covers a total of 12,000 m2 (130,000 sq ft), including the 10,000 m2 (110,000 sq ft) building and 2,000 m2 (22,000 sq ft) outdoors (excluding parking spaces).