Because of its central location, the island has been important to the communications and commerce in the region. The settlement of Nötö has been dated to the early 11th century, and the assumption is that vikings stopped by during their travels and possibly even settled on the island.
A culturally and historically valuable village consisting of old farms ('hemman') still exists on the island. In the centre of the village there is a windmill, and a few minutes away from the village harbour there is a chapel, inaugurated in 1757. During the summer season, there is a cafeteria in the old primary school building, where e.g. various art exhibitions are held.
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.