The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
Wikipedia[2] gives 20 March 2019, and the date holds up against the contemporary press: Aftenposten ran "Nå åpner Under. Slik ser det ut i havdypet" on 19 March 2019, the eve of the opening. Secondary coverage that says only "early 2019" or "launched in 2019" does not narrow it further.
Gives the opening date of 20 March 2019, the address at Bålyveien 50, the dimensions (495 square metres, 34 metres across, 5.5 metres down, an 11 by 3.4 metre window), the 40 covers, the sea-lab role and the Michelin star awarded inside the first year. Its own citation for the opening is Aftenposten of 19 March 2019.[1]
Visit Norway's page, used for the Michelin star ("In 2020, the restaurant also received a one-star Michelin rating, which it holds to this day") and for head chef Bernt Sætre's approach. It disagrees with the architects on capacity, saying "room for up to 90 guests" where Snøhetta and Wikipedia[2] both say 40 seats in the dining room.
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.