The archaeological remains found near the Águila Castle seem to confirm the presence of a pre-islamic population, maybe from the Roman Age.
Apparently in 914 the inhabitants of the fort looked like emirales troops burned the city of Algeciras ships that supported the revolt on Ibn Umar Hafsun, in any case the construction of the castle had to be early to be this hard hit area by Berber rebellions and Mozarabic.
The castle was restored in 1839 after it was conquered by French army in 1810. It was however badly damaged in the explosion in 1842.
The Águila Castle is the most representative monument in Gaucin, from the fortress you can see stunning views, in a clear day you can even see the North of Africa.
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.