Festival of the Sea is an extension of Fisherman's Day, an Icelandic annual holiday usually held the first Sunday in June. Fisherman's Day has been celebrated since 1938 to honor the hard work and sacrifices of the Icelandic fisherman.
On March 18th Iceland opens it's borders to all travellers that have been vaccinated by approved vaccination by the EU or travellers that can prove they have antibodies, without quarantine or any restrictions.
Beer was illegal in Iceland for most of the 20th Century and the prohibition finally ended on March 1, 1989. This is why Icelanders celebrate Beer Day on March 1st. (We had to fought for our right to party!)
In 1967 John Lennon asked Yoko Ono to create a piece tower for him in their backyard. She apparently never got to it back then, however 40 years later she did, just not in her backyard, but in Reykjavík Iceland.