Iceland is built for far-flung naval exploration and coastal raiding rather than settling nearby — a civilization that rewards sailing to the edges of the map more than developing the land right around your capital.
"Kringla Heimsins" grants Culture when you discover a Natural Wonder, with a much larger reward for discovering one specifically in Distant Lands, plus a Relic every time you master a Civic — at the cost of reduced Production and increased Gold cost for training Missionaries.
The Víkingr is a unique Naval unit built around Coastal Raiding and pillaging, especially strong when sailed up Navigable Rivers with the right Civic unlocked to extend its raiding range.
The associated Wonder, Reykjaholt, grants Culture and increased Production toward Military Units for every Great Work in its city, has dedicated Relic slots, and must be placed on Tundra.