The world's deepest swimming pool opened on Saturday in the Polish town of Mszczonow, near Warsaw.
The swimming pool, called 'Deepspot,' is 45.4-metres-deep and filled with 8,000 cubic metres of water - more than twenty times the volume of a standard 25-meter-long pool.
The venue features reproductions of underwater caves and Mayan ruins, as well as a small shipwreck that can be explored.
Unlike ordinary pools, the 'Deepspot' complex can accommodate customers during the COVID-19 pandemic, as it is considered a training centre for divers.
"There is no beautiful fish or coral reefs here, so it is not a substitute for the sea, but it is really a good place to learn and train in order to dive safely," said Przemyslaw Kacprzak, a 39-year-old scuba instructor who was among those attending the swimming pool's opening.
"And that's funny! It's like a kindergarten for divers!" he added.
The swimming pool is also going to be used by firefighters and the army.
The construction lasted two years and cost 40 million zlotys (€8.9 million). Around 5,000 cubic metres of concrete were used.
Despite its immense size, 'Deepspot' is however set to lose its crown soon, as a new, 50-meter-deep swimming pool, called 'Abyss,' is set to open in Merseyside, UK, in 2021.