Brno to build one of Europe's largest aquariums, with 55-meter underwater tunnel

Brno is set to transform part of its sprawling exhibition grounds into a massive public aquarium featuring hundreds of species and a 55-meter underwater tunnel, in a project its developers say will rank among the largest aquariums in Europe.

The attraction, provisionally called Green Planet: National Aquarium, will take over Pavilion C at the Brno Exhibition Centre along with surrounding outdoor areas. Plans call for around 100 aquariums and tanks holding more than 4 million liters of water and approximately 400,000 individual animals.

The privately financed project carries an investment of at least CZK 700 million. Construction is scheduled to begin in 2027, with organizers aiming to welcome the first visitors in the second half of 2028.

The centerpiece will be a 2.5-million-liter ocean tank crossed by an approximately 55-meter underwater tunnel, allowing visitors to watch marine life swimming above and around them.

Around 500 animal species are expected to inhabit the aquarium, including rare species. Exhibits will represent aquatic ecosystems from North and South America, Africa, Asia, Australia and Europe as well as the world's seas and oceans.

The project will encompass about 8,000 square meters of indoor visitor space and another 14,000 square meters outdoors.

Brno officials expect the aquarium to become a significant regional attraction. Mayor Markéta Vaňková said projections anticipate around 500,000 visitors during its first year, potentially rising to 650,000 annually.

About 65 percent of visitors are expected to come from outside Brno, with roughly 30 percent traveling from abroad. Its location could make the aquarium a destination for visitors from neighboring Slovakia and Austria as well as Poland and Germany.

The project will also include educational facilities, a café, shop and event spaces. Interactive attractions are expected to include virtual diving and other immersive technology.

The agreement between developer JVS Holding Group and city-owned Veletrhy Brno gives the project a permanent home in Pavilion C without restricting the exhibition center's primary trade fair operations.

Preparations will continue through 2026, followed by construction next year. Aquarium technology is due to be installed in 2028, after which tanks will need to undergo biological stabilization before animals are gradually introduced.

The developers say water consumption will be reduced through closed recirculation systems that clean and return water to the tanks. Rainwater retention facilities are also planned at the exhibition grounds.

Scientists from the Czech Academy of Sciences' Institute of Vertebrate Biology are advising on the exhibits, with the aquarium intended to combine a visitor attraction with programs covering zoology, biodiversity, ecology and conservation.

International specialists involved in the project include experts with experience developing SEA LIFE aquariums as well as public aquariums in Turkey and Abu Dhabi.

Czechia already has smaller aquarium attractions, including a freshwater aquarium with a walk-through tunnel in Hradec Králové and the Sea World aquarium in Prague's Holešovice district.

Brno's project, however, is being conceived on a considerably larger scale. If the current schedule holds, visitors could be walking through its 55-meter underwater tunnel before the end of 2028.