The beginnings of Maria Weißenstein go back to 1553 when Holy Mary appeared to the miner Leonhard Weißensteiner. He built a chapel which soon became a place of pilgrimage. The first Baroque church was built in 1673 and renotaved 1719-1722. The three towers were demolished in the late 1700s when the monastery was dissolved. The reconstruction began in 1800.
In August, 1885, the image of the grieving Madonna, which Leonhard Weissensteiner had kept in the chapel, was crowned again by Giovanni Giacomo della Bona, Bishop of Trient, in a ceremony attended by over 130 priests and 15,000 believers. Today the friars of the Servite Order live in the monastery and take care of a hostel.
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.