Origins of the Château Bilquin de Cartier can be traced back to the around 1635, when the Honoré family built a castle on the Sambre river bank. The place had formerly been occupied by a seigneurial manor which was destroyed on 21 July 1554.
In 1667, the unfinished Spanish fortress of Charleroy was captured by Louis XIV's troops during the War of Devolution. As the castle in Marchienne was located in neutral territory (under authority of the Prince-Bishopric of Liège), it was used as a hospital for both French and Spanish soldiers.
In 1695, the castle was bought by Guillaume de Bilquin, a wealthy forge owner, who completes and enhances it. Later the castle became the property of the Cartier de Marchienne family. It was severely damaged by a fire in 1932, and bought over by the municipality of Marchienne-au-Pont in 1938, ending more than two centuries of ownership by the Cartier family.
The castle today hosts a public library on the ground floor (Bibliothèque Marguerite Yourcenar), and administrative services of the Walloon region on the first floor.
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.