The lighthouse station on Ursholmen, in Sweden’s Kosterhavet National Park, was opened in 1891. Twin towers were used to distinguish this station from others. The second light was disabled in the 1930s, when technology had advanced to produce characteristic flashing patterns with a single light, but the tower still remains. Ursholmen also is known for “roads” of black diabase created far in its geological past, when the bedrock contracted and cracked and molten rock filled the cracks and cooled.

While anchored in the Koster Islands, we ran the tender over to visit the lighthouse station at tiny Ursholmen, and check out it unusual geological formations.

Below are trip highlights from September 23rd, 2019. Click any image for a larger view, or click the position to view the location on a map. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps.

Sunrise Position: 58°51.40’N, 11°1.66’E Sunrise from our anchorage in the Koster Islands.

Dirona Position: 58°51.31’N, 11°1.27’E Another warm, calm and sunny day in the Koster Islands.

Tender Position: 58°50.02’N, 10°59.58’E Our tender, in the distance, tied to a ring along the shoreline of the Ursholmen to visit the lighthouse there.

Ursholmen Lighthouse Position: 58°49.95’N, 10°59.41’E The lighthouse station on Ursholmen was opened in 1891. Twin towers were used to distinguish this station from others. The second light was disabled in the 1930s, when technology had advanced to produce characteristic flashing patterns with a single light. The light was automated in 1965.

Diabase Position: 58°50.00’N, 10°59.36’E Far in its geological past, the bedrock on Ursholmen contracted and cracked and molten rock filled the cracks. When cooled, the molten rock formed these “roads” of black diabase.

Rock Pool Position: 58°50.00’N, 10°59.32’E This tranquil rock pool on the west side of Ursholmen is a popular place for a saltwater dip. Two people had arrived for a soak as we were leaving.

Snack Position: 58°50.01’N, 10°59.33’E Enjoying a snack on Ursholmen overlooking the rock pool.

Bench Position: 58°50.01’N, 10°59.54’E Looking west over the small village on Ursholmen from a bench ashore.

Lighthouse from Tender Position: 58°49.84’N, 10°59.48’E View to the Ursholmen light on pass around the island in the tender.

Ferries Position: 58°53.42’N, 11°0.36’E The number of ferries berthed in the Koster Islands gives an idea of how busy it gets here in the summer.

Empty Position: 58°53.67’N, 11°0.86’E When we passed this marina two days ago on a Saturday, the place was packed, with boats rafted three deep. Today, on Monday, the crowds are gone and the marina is near-empty.

Click the travel log icon on the left to see these locations on a map, with the complete log of our cruise. On the map page, clicking on a camera or text icon will display a picture and/or log entry for that location, and clicking on the smaller icons along the route will display latitude, longitude and other navigation data for that location. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps.