Stora Karlsö

History

Ancient Beginnings

About 9,000 years ago, seal hunters from Gotland's earliest culture ventured to the island for hunting. These Stone Age people were fishers and hunters who lived off nature's bounty. They crafted tools like spear tips, awls, axes, and vessels from bone, stone, horn, and clay.

Many Stone Age artifacts were discovered in the large cave called Stora Förvar. An excavation in the late 1800s unearthed about 7,000 finds, mostly from the Late Stone Age. Researchers believe the cave was used regularly for nearly 10,000 consecutive years!

Bronze Age Monuments

During the Bronze Age, several impressive cairns were built on the island. Röjsu, the largest, sits at the island's highest point. In its center grows "Linnaeus' Ash," named after Carl von Linnaeus's 1741 travel description. On the southern side of the island stands Lauphargi, another Bronze Age cairn with a well-preserved stone wall. These cairns are approximately 3,000 years old.

Iron Age Remains

The Iron Age left behind over 70 graves. It's possible that Stora Karlsö was a busy trading post during this time. Near Norderhamn, on the island's north side, there's a fan-shaped row of depressions. While their purpose is debated, some theorize they're boat graves, while others suggest they might be Viking Age boat landings.

Medieval Stone Quarrying

Intensive quarrying took place during the Middle Ages. The sought-after pink "Karlsö marble" was transported for use in Gotland's church construction. Today, clear traces of this quarrying can be seen on the southern part of the island. The quarries remain untouched since the workers left 700-800 years ago.

19th Century: Fishing Village and Bird Hunting

In the 1800s, Stora Karlsö was popular for its excellent fishing. Norderhamn had a large fishing village with up to 80 fishing huts at its peak. Today, only two of these huts remain.

During this period, reckless hunting nearly wiped out the auk birds. By 1880, the number of guillemots was estimated at only 20-30 individuals. Hunting was mostly for sport and often occurred during the breeding season when birds are most vulnerable to disturbances. Egg collection for food was also common.

Conservation Efforts

Between 1880 and 1887, a newly formed company – Karlsö Jagt- och Djurskyddsförenings AB – gradually bought the land on Stora Karlsö. This company, which still owns the island today, was driven by Willy Wöhler, who even persuaded King Oscar II to buy a share. The company gradually banned all bird hunting, saving the guillemot population on Stora Karlsö.

Interestingly, the island is the world's second-oldest protected natural area, after Yellowstone National Park in the USA. Since 1970, Stora Karlsö has been a nature reserve.

Sheep Grazing and Vegetation

Sheep have always been important to Stora Karlsö. Research shows they've been present since the Late Stone Age (about 6,000 years ago). Linnaeus's 1741 journey account describes the island as almost completely grazed bare.

When the Karlsö company took over in 1887, sheep grazing stopped as the company was more interested in hare hunting. Willy Wöhler also worked hard to plant trees and bushes on the island. During the 1900s, both the auk birds and vegetation recovered.

By the late 20th century, the island had become overgrown. Areas once covered with orchids were now thick with juniper bushes, blackthorn, and bird cherry. In 1995, efforts began to clear parts of the island and reintroduce sheep grazing. After a 108-year break, sheep once again grazed on Stora Karlsö. This successful experiment has largely restored the island's open heathland with orchids and grazing-friendly flowers.

The Lighthouse

In 1887, a lighthouse was built on Stora Karlsö, bringing a permanent population to the island – at most, four families. In the 1930s, a lighthouse keeper's residence was built, which, along with the impressive lighthouse, is now classified as a historic building.

In 1974, an electric cable was extended to the island, allowing the lighthouse to be automated. Year-round staffing continued for several years, but now there's no permanent population on the island. From May to August, visitors can stay overnight in the lighthouse and associated buildings. The island's caretaker also has an apartment in the lighthouse.

Geology and Ecosystem

Stora Karlsö is a rocky island in the Baltic Sea, a remnant of ancient seabeds teeming with coral reefs that have transformed into limestone over millions of years. The island's distinctive shape features steep cliffs on all sides except the south, where the limestone layers gently slope downward. To the north, the rock face is split by the welcoming gap of Norderhamn. The cliff faces are impressive, reaching heights of 25-45 meters in many places.

Formation and Geological History

The hard reef limestone that forms the island was created over 400 million years ago during the Silurian period. At that time, Gotland (the main island) was located near the equator. With water temperatures approaching 30 degrees Celsius, conditions were perfect for the corals that built up the Karlsö Islands.

Stora Karlsö itself consists of two coral reefs from this era. The surrounding material is composed of dead marine plants and animals mixed with clay silt, which formed limestone over millions of years. Near the Hunting Pavilion in Hien, visitors can explore a fossil collection showcasing traces of life from when the island was formed. This includes honeycomb coral (Favosites), chain coral, stromatoporoids (sometimes called "cat skulls"), crinoid stems, and much more.

Visitors are welcome to pick up, examine, and study fossils on the island, but it's important to note that removing them from the site is not allowed.

Cave Systems

The island boasts over twenty caves, with several larger ones located around Norderhamn on the northern side. The largest, Stora Förvar, is 25 meters deep and contains unique cultural layers from the Stone Age that have been extensively studied.

Alvar Landscape

The island's plateau is an alvar, an almost treeless grassland shaped by long-term sheep grazing. Alvar is a rare type of natural environment found primarily on Öland and Gotland, with only a few other locations in Sweden and the rest of the world. It is characterized by flat terrain on limestone bedrock with thin or no soil cover.

For over a hundred years without grazing, the heath became overgrown with bushes. Recently, the pastoral landscape has been restored—shrubs and thickets have been cleared away, and sheep have been reintroduced. This restoration has benefited drought-tolerant and light-demanding alvar plants, including the many orchid species found on Stora Karlsö.