The Freudenberg castle was one of the largest castles in region. The main castle dates from the first half of the 13th century and consists of a keep with a trapezoid floor plan. The curtain wall was 80m long and 60m wide and protected by a round tower in the southwest corner.
The castle was built by the Lords of Wildenberg. Later it was owned by several families and the imperial Austria. Because of a dispute over the legacy of the last Count of Toggenburg Freudenberg was besieged on May 26, 1437 by troops from Zurich. The castle was taken by the besiegers, plundered and set on fire.
Since 1985 the site has been owned by the municipality of Bad Ragaz and can be visited freely.
Towering 52 meters above the sea, Bengtskär lighthouse is the tallest one in Scandinavia. The building started in in 1905 after the shipwreck of S/S Helsingfors and was completed in 1906. The lighthouse was designed by architect Florentin Granholm. On December a special petrol lantern, designed and built in Paris, was brought to Bengtskär and installed atop the tower.
German fleet bombarded Bengstkär in the First World War in 1914. Since the Gulf of Finland was heavily mined, it was not until 1919 that the surrounding seas were declared safe for shipping, that the light was lit again.
After the war the military value of Bengtskär increased as part of the defence system of independent Finland. In Second World War (1941) Soviet Union made a suprise attack to island. After a bloody battle, the small Finnish garrison emerged victorious. Intermittent repairs to the facility continued during the post-war period.