Noboribetsu Marine Park Nixe, Public aquarium in Noboribetsu, Japan.

Noboribetsu Marine Park Nixe is an aquarium in Noboribetsu designed to look like a Danish castle, displaying thousands of sea animals across different themed zones. The exhibits spread across multiple levels with tanks for fish, penguins, seals, and dolphins.

Noboribetsu Marine Park Nixe opened on 20 July 1990, funded by 42 local companies and the city of Noboribetsu at a total cost of about 7.3 billion yen. In 2001 the city transferred management to the private operator Kato Kanko, which cut staff and expanded foreign visitors; the park returned to a single-year profit in 2006.

The central castle, called Nixe Castle, is modelled on Egeskov Castle in Denmark. Around it stand Nordic-style buildings housing souvenir shops and the dolphin, sea lion and penguin show venues. A penguin parade crosses the square in front of the castle all year, with king, gentoo or Cape penguins depending on the season.

The aquarium is five minutes on foot from Noboribetsu Station and is open daily. Plan enough time to explore all levels, especially if you want to see the feeding demonstrations and live shows.

The castle is modelled on Egeskov Castle in Denmark, and its interior holds a crystal tower tank 8 metres tall plus two aquarium tunnels. In the touch pool visitors can handle not only starfish and sea cucumbers but also rays and horseshoe crabs.