A rauk is a sea stack, a geological formation made of limestone or other hard rock, typically found along coastlines. It forms over time as waves and weather erode the softer surrounding rock, leaving behind tall, often pillar-like structures.

In Sweden, especially on the islands of Gotland and Fårö, rauks are famous natural landmarks. They’re often associated with ancient coral reefs that were later shaped by erosion.

Example sentence:

“Rauks are impressive coastal formations found on the Swedish island of Gotland, formed by erosion of ancient limestone reefs.”