Construction works of the impressive church of Nuestra Señora de la Asunción began in the early 16th century. It was built on a former castle, the walls of which can still be appreciated in the main portal. Its nave is extraordinarily high and has a hall plan.
It is covered with ribbed vaults forming a star, which become even more intricate on their higher section, over the choir. Also worth mentioning is the access to the choir through a magnificent staircase with a stone handrail, covered with an oval vault in cut stone masonry and upper and lower doors decorated with pilasters. Its baptism font is a complete work of art; built on a ribbed column, it is covered in paneled decorations dating back to the 17th century. The main altarpiece is one of the most outstanding pieces of its kind in La Rioja region. It was built in the 16th century and gilded in the 17th century. A good number of the figures depicted narrate the life of Christ, his birth and childhood. There are also images of San Juan and Nuestra Señora del Rosario.
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.