The Largest Aquarium in the World (2026) & Natural Seawater Tanks
The largest aquarium in the world is Chimelong Spaceship in Zhuhai, China. Guinness World Records certified it in September 2023 at 75,350,969 litres (about 19.9 million US gallons) across 38 tanks, and it also holds the record for the largest single aquarium tank, at 56,450,136 litres. That is still the record as of October 2026.
Below you will find the ten biggest aquariums on Earth ranked by total water volume, the UK’s largest aquariums, and which giant aquariums run on natural seawater pumped from the ocean rather than water mixed from salt, with the figures checked against official sources.
Updated October 2026 by the team at Natural Seawater Supplier, a Croydon, London-based supplier of live natural seawater for marine aquariums, delivering across the UK 7 days a week.
Key takeaways
- Chimelong Spaceship in Zhuhai, China, is the world’s largest aquarium: 75,350,969 litres in 38 tanks, certified by Guinness World Records in September 2023.
- Its main tank, at 56,450,136 litres, is also the world’s largest single aquarium tank.
- SeaWorld Abu Dhabi (about 58 million litres, opened 2023) is usually ranked second, ahead of Chimelong Ocean Kingdom (48.75 million litres), which held the record from 2014 to 2023.
- The UK’s largest aquarium tanks hold about 2.5 million litres each: the Atlantic Ocean tank at the National Marine Aquarium in Plymouth and Endless Ocean at The Deep in Hull.
- Okinawa Churaumi Aquarium in Japan is the best-known natural seawater giant, drawing water from about 300 m offshore at a depth of 20 m.
What is the largest aquarium in the world in 2026?
Chimelong Spaceship, a spaceship-shaped indoor marine park on Hengqin Island in Zhuhai, Guangdong, opened in 2023 and took the record from its sister park, Chimelong Ocean Kingdom, next door. According to Guinness World Records, its 38 tanks hold 75,350,969 litres and house nearly 300 kinds of fish, coral and aquatic plants. Guinness quotes the volume as 16,574,889 gallons; that figure is in UK (imperial) gallons, which works out at about 19.9 million US gallons.
The park won seven Guinness titles when it opened, including the largest aquarium tank: a single vessel of 56,450,136 litres, 125.4 m long, 12–32 m wide and 11 m deep. For scale, that one tank holds more than 20 times the water of the biggest tank in the UK.
The 10 biggest aquariums in the world, ranked
Rankings are by total water volume across all tanks, the measure Guinness uses for its largest aquarium record. Volumes come from Guinness World Records where certified, and otherwise from the aquariums’ published figures; US gallons are converted from litres.
| # | Aquarium | Location | Opened | Total volume (litres) | US gallons (approx.) | Natural or artificial seawater? |
|---|---|---|---|---|---|---|
| 1 | Chimelong Spaceship | Zhuhai, China | 2023 | 75,350,969 | 19.9 million | Not published |
| 2 | SeaWorld Abu Dhabi | Yas Island, UAE | 2023 | about 58,000,000 | 15.3 million | Not published |
| 3 | Chimelong Ocean Kingdom | Zhuhai, China | 2014 | 48,750,000 | 12.9 million | Not published |
| 4 | Singapore Oceanarium (formerly S.E.A. Aquarium) | Sentosa, Singapore | 2012; reopened expanded 2025 | about 45,000,000 | 11.9 million | Not published |
| 5 | Georgia Aquarium | Atlanta, USA | 2005 | 41,640,000 | 11.0 million | Artificial, mixed on site |
| 6 | L’Oceanogràfic | Valencia, Spain | 2003 | 41,600,000 | 11.0 million | Not confirmed by operator |
| 7 | Port of Nagoya Public Aquarium | Nagoya, Japan | 1992 | 27,000,000 | 7.1 million | Not published |
| 8 | Moskvarium | Moscow, Russia | 2015 | 25,000,000 | 6.6 million | Not published |
| 9 | National Museum of Marine Biology and Aquarium | Pingtung, Taiwan | – | 24,142,000 | 6.4 million | Not published |
| 10 | The Seas with Nemo & Friends (EPCOT) | Florida, USA | 1986 | 21,580,000 | 5.7 million | Not published |
Figures for SeaWorld Abu Dhabi and the rebuilt Singapore Oceanarium are the widely reported totals; neither has a certified Guinness volume. Some lists rank aquariums by their largest single tank instead, which reshuffles the order: Georgia Aquarium’s Ocean Voyager tank (about 6.3 million US gallons) and Chimelong Ocean Kingdom’s whale shark tank (22.7 million litres) both rank highly on that measure.
Other famous giants
| Aquarium | Location | Opened | Volume | Seawater |
|---|---|---|---|---|
| Dubai Aquarium & Underwater Zoo | Dubai Mall, UAE | 2008 | about 10 million litres in the main tank | Not published |
| Okinawa Churaumi Aquarium | Motobu, Japan | 2002 | about 10,000 m³ in total; Kuroshio Sea tank 7,500 m³ (7.5 million litres) | Natural, pumped from offshore |
| Monterey Bay Aquarium | California, USA | 1984 | Smaller, but famous for its open seawater system | Natural, pumped from Monterey Bay |
What is the biggest aquarium in the UK?
The National Marine Aquarium in Plymouth, run by the Ocean Conservation Trust charity, describes itself as the UK’s largest aquarium. It opened in May 1998, and its Atlantic Ocean tank holds about 2.5 million litres, making it the deepest tank in the UK.
The Deep in Hull, opened in 2002, has a tank of similar size: Endless Ocean holds about 2.5 million litres and 87 tonnes of salt and is over 10 m deep.
| UK aquarium | Location | Opened | Largest tank | Seawater |
|---|---|---|---|---|
| National Marine Aquarium | Plymouth | 1998 | Atlantic Ocean tank, about 2.5 million litres | Not published |
| The Deep | Hull | 2002 | Endless Ocean, about 2.5 million litres | Artificial: salt mixed into RO-filtered tap water |
Which big aquariums use natural seawater?
Public aquariums by the sea often pump water straight from the ocean, because natural seawater arrives with the right chemistry, trace elements and living plankton. Inland aquariums, or those beside estuaries and polluted harbours, have to make their own.
Okinawa Churaumi Aquarium, Japan
Churaumi is the classic natural seawater giant. According to the aquarium’s official facility data, seawater is drawn from about 300 m offshore at a depth of 20 m, at up to 3,000 m³ per hour, through a 1.8 m conduit and eight large filters. That water supplies the 7,500 m³ Kuroshio Sea tank, home to whale sharks and manta rays.
Monterey Bay Aquarium, USA
Monterey Bay Aquarium in California runs an open seawater system, pumping up to about 2,000 US gallons a minute from the bay through two intake pipes into exhibits such as its three-storey kelp forest.
Marine Biological Association, Plymouth
In the UK, the Marine Biological Association’s research aquarium in Plymouth pumps natural seawater directly from Plymouth Sound through a permanent pipeline into its recirculating systems.
Aquariums that make their own seawater
Georgia Aquarium in Atlanta is hundreds of miles from the sea, so it makes saltwater in large on-site mixing tanks. The Deep in Hull sits on the Humber, but the estuary’s salinity swings with every tide. The Deep explains that it stores tap water, passes it through reverse osmosis, then mixes in salt a tonne at a time in a 30,000-litre chamber to reach 33 ppt, using around 100 tonnes of salt a year.
Why do big aquariums care about natural seawater?
- Biology. Natural seawater carries bacteria, phytoplankton and zooplankton that help process nutrients and feed filter feeders.
- Chemistry. It already has the ocean’s balance of major and trace elements, so less dosing is needed.
- Nutrient control. Large fish produce a lot of waste. Regular exchange with clean seawater helps keep nitrate and phosphate down, as our guide to nutrient export in marine aquariums explains.
- Cost at scale. For a coastal aquarium, pumping and filtering seawater can be cheaper than buying hundreds of tonnes of salt each year.
The trade-off is that the water must be collected from clean, open water and filtered, and supply depends on location. That is why inland and estuary aquariums mix their own, just as many home reefkeepers do.
Can you use natural seawater in a home aquarium?
Yes. Home aquarists can enjoy the same benefits the big public aquariums do, without an offshore pipeline. We explain the pros and cons in natural sea water vs synthetic salt mix, and how reefkeepers switch safely in why natural seawater is a game-changer for reefkeepers. If you are just starting out, our saltwater aquarium guide for beginners and reef tank setup guide cover the essentials.
Natural Seawater Supplier delivers natural seawater across the UK, 7 days a week, and new customers can try 25 litres free.
Bring real seawater home
Like the big public aquariums, your tank can run on natural seawater. Find out where to buy sea water in the UK. Get a quote for your postcode or claim 25 litres free, or call 020 7183 4175.
Frequently asked questions
What is the largest aquarium in the world?
Chimelong Spaceship in Zhuhai, China, is the largest aquarium in the world. Guinness World Records certified it in September 2023 at 75,350,969 litres across 38 tanks, and it remains the record holder as of October 2026.
What is the biggest aquarium tank in the world?
The biggest single aquarium tank is also at Chimelong Spaceship in Zhuhai, China. It holds 56,450,136 litres and measures 125.4 m long, 12 to 32 m wide and 11 m deep, according to Guinness World Records.
What was the largest aquarium before Chimelong Spaceship?
Chimelong Ocean Kingdom, its sister park in Zhuhai, held the largest aquarium record from 2014 to 2023 with 48.75 million litres. Before that, S.E.A. Aquarium in Singapore and Georgia Aquarium in Atlanta were among the record holders.
What is the largest aquarium in the UK?
The National Marine Aquarium in Plymouth describes itself as the UK’s largest aquarium. Its Atlantic Ocean tank holds about 2.5 million litres. The Deep in Hull has a similarly sized tank, Endless Ocean, at about 2.5 million litres.
Do big aquariums use real seawater?
Many coastal aquariums do. Okinawa Churaumi Aquarium pumps natural seawater from about 300 m offshore, and Monterey Bay Aquarium draws water straight from the bay. Inland or estuary aquariums such as Georgia Aquarium and The Deep in Hull make their own seawater by mixing salt into purified water.
How big is the biggest aquarium in the US?
Georgia Aquarium in Atlanta is the largest aquarium in the United States, holding about 41.6 million litres (11 million US gallons) in total. Its Ocean Voyager tank alone holds about 6.3 million US gallons.
Sources
External sources cited in this article (checked October 2026):
- Largest aquarium record (Guinness World Records)
- Aquarium’s official facility data (Okinawa Churaumi Aquarium)
- How The Deep makes its seawater (The Deep)
Bottom line
As of October 2026, the largest aquarium in the world is Chimelong Spaceship in Zhuhai, China, at 75.35 million litres, with SeaWorld Abu Dhabi and Chimelong Ocean Kingdom close behind. In the UK, Plymouth and Hull each have tanks of around 2.5 million litres. Coastal giants like Okinawa Churaumi show what natural seawater can do at scale, and the same water can work in your own tank at home.