Den Blå Planet — The Blue Planet

Den Blå Planet — officially the National Aquarium Denmark — opened on 22 March 2013 in Kastrup, a coastal district just four kilometres from Copenhagen Airport and directly on the Øresund strait. Replacing the ageing Danmarks Akvarium, which had operated since 1939 in Charlottenlund, the new facility was built to bring Denmark's national aquarium into the 21st century with both scientific ambition and architectural boldness. The Danish architectural firm 3XN designed the building in the form of a giant whirlpool, its five curved wings radiating outward from a central hub, clad in 26,000 aluminium shingles that shimmer silver and blue as the light shifts across the waterfront facade. The form was conceived to evoke water in perpetual motion, and from above the structure is unmistakably shaped like a vortex pulling visitors inward.

Inside, the aquarium spans over 10,000 square metres and houses more than 20,000 animals across 53 individual aquariums. The habitats range dramatically in geography and ecology: visitors move from the flooded forests and piranhas of the Amazon River basin, through the vivid coral reefs of the Indian Ocean, to the cold-water species of the Arctic and the North Atlantic — waters that surround Denmark itself. The largest single tank holds one million litres of water and is home to sand tiger sharks, manta rays, and schools of open-ocean fish that circle in a slow, mesmerising procession. A walk-through transparent tunnel runs beneath this tank, placing visitors directly inside the reef environment with fish passing overhead and on all sides.

Among the most distinctive experiences is the freshwater section, which traces river systems from their mountain sources to tropical deltas, and the touch pool area where visitors can handle starfish and sea urchins under staff supervision. The rainforest and crocodile zone introduces terrestrial animals that depend on aquatic ecosystems, bridging the boundary between sea and land habitats. Den Blå Planet also operates active research and conservation programmes, participating in breeding initiatives for threatened species including the European eel, whose population has declined by over 95% since the 1980s.

Den Blå Planet is reachable by Metro Line M2 to Copenhagen Airport, followed by a short walk or the dedicated shuttle — the entire journey from central Copenhagen takes approximately 20 minutes. The aquarium is open daily, with evening events and behind-the-scenes tours available for advance booking. Arrive early on weekends and Danish school holidays, when the central atrium fills quickly. The waterfront terrace café offers direct views across the Øresund toward Sweden, making it a worthwhile stop even after you have finished exploring the tanks.