It seems to be an open air activity that is a part of "Øresundsakvariet"

https://www.oresundsakvariet.ku.dk/nyheder/2024/sommer/

"Guided tours to the Water Lab
From June 22 through August 31, we will be exploring the Water Lab and feeding the animals. You can join guided tours where guides will explain the unique wildlife of the Øresund, feed the fish and help catch shore crabs.
The activity takes place three times daily at 12:25, 14:25 and 16:25. We walk together from the aquarium's main entrance down to the Water Laboratory, where you can borrow equipment to catch crabs. You can also try out one of our water binoculars and take a closer look at the exciting wildlife hiding under the surface."
Translated with DeepL.com (free version)

The area is open 24/7 for any activities like fishing crabs.

I will admit that the spot is not tourist=aquarium

Could it be this combination
tourist=information
information=water_activity
