The construction of Under, the world’s largest underwater restaurant, is finished. It is located on the shoreline near the village of Båly in Norway. The company behind the project, Snøhetta, said that the 495-square-metre restaurant is designed to resemble a sunken periscope. Under has a large panoramic window in the front, enabling its visitors a glimpse into marine life.

The restaurant which can take up to 40 guests will have another purpose – it will also serve as a marine research centre.

Lead architect of Under, Rune Grasdal said that for most of the people involved, this is an entirely new experience. There are restaurants located in aquariums, but this one is located in the North Sea. Grasdal stated that when the weather is bad in that region, it can be very rough. However, this enables visitors a different experience, being inside safe while outside nature shows its face.

The company wanted Under to be as simple as it can be. Because of that, they have come up with this design – the whole structure is in a shape of a monolithic tube that is 34 metres long. The walls of the structure are half-a-metre thick and are slightly curved, to provide the best possible resistance against the outside weather.

Grasdal stated that they wanted to create a tube that will take the people from above sea level to below the surface of the sea. The way that they have chosen is the most effective way to do it. Furthermore, visitors are going to feel secure, but not claustrophobic.

On the outside, the architects decided to leave the concrete exposed, to attract molluscs and algae to cling on. As time goes by, the building will become an artificial mussel reef that will help purify the water and draw more marine life.

The restaurant has an untreated oak-clad entrance. According to the company, the material will naturally fade into grey, to complement the exposed concrete. The oak is also used throughout the interior, with the intention for it to contrast the cold exterior.

Under has three levels which include the main restaurant, a champagne bar, cloakroom and a foyer. A giant oak staircase connects everything inside.

The main feature of the restaurant is the large panoramic acrylic window. It can be seen from any level. It is 11 metres long and three metres tall. The champagne bar features a large vertical window, letting through daylight and enabling visitors a view of the sea level.

Snøhetta wanted for the visitors of Under to be able to observe sea life even during the night. This is why they installed soft lighting on the sea bed. Heidi Pettersvold Nygaard, the senior interior architect, said that they wanted to create a gradient effect with light to deeper colours.

The main dining room features terrazzo flooring paired with green-hued acoustic panels and deep blue tones, inspired by the sea bed. The above champagne bar has warmer orange and pink hues, inspired by sand and sea shells. The interior also has unique furniture. The ceramics used are designed by local artist, paired with angular chairs and charred oak tables.

Most of the people would think that being five metres underneath the water would be claustrophobic, but this is not the case in Under. Grasdal believes that this is due to the warm atmosphere. Natural materials along with fabric lining have created a nice and soothing atmosphere.

Under is intended to be much more than a restaurant. Its creators are hoping to inform the public about the biodiversity of the sea through its menu and architecture. When the restaurant is not working, it will become a lab for marine biologists that are going to study fish behaviour. To be more precise, they want to see whether it is possible to train fish to react to sounds and to see if they act differently in different seasons.

This is the first underwater structure designed by Snøhetta, even though they have several waterside buildings like the hotel for the Lofoten archipelago and the Oslo Opera House. The company was founded in 1989 by architects Kjetil Trædal Thorsen and Craig Dykers. They have offices in Oslo, San Francisco, New York, California, Austria, Innsbruck, Stockholm and Singapore.