Hässelby läde - Stora Karlsö, Gotlands Län, Sweden - Natural Arches on Waymarking.com

The island of Stora Karlsö, like the neighboring islands of Gotland and Öland, was formed during the Cambrian period around 550 million years ago. In the nearly 60 million years that followed, layer upon layer of sand and dead animals, which later became fossils, were deposited on the seabed, forming limestone and sandstone formations, while coral reefs also provided denser material the turned into harder stone pillars. In the subsequent ice ages, parts of the island were eroded by the ice, between the ice ages the water of the Baltic Sea caused further erosion and thus formed the rauks, until the land surface finally rose above the water due to the post-glacial land elevation around 11,500 years ago and thus stopped the erosion process.

The rock arch that was preserved in this way and was called "Hesselby Läde". The name goes back to fishermen from Hesselby, who stored equipment for their trade here on the island at the arch, as this provided a certain degree of protection from the weather. The arch itself has a clear height of about 9m and is about 4m wide on the ground.

As early as 1880, the island, with its then highly endangered bird life, was placed under special protection at the instigation of Willy Wöhler and is therefore the oldest nature reserve in Sweden. The island can be visited only from May to the end of September as part of a boat tour from Klintehamn on Gotland.

Quellen:
- Aron Hejdström: "Inselführer Stora Karlsö", German edition, page 26.
- Hässelby Läde, storakarlso.se, Swedish language