Construction of the Porrentruy castle took place between the mid-13th century and the beginning of the 18th century. The oldest part is the thirteenth century Réfous Tower. 14th century ramparts survive on the western and northern sides.
During the reign of Prince-Bishop Jacob-Christoph Blarer of Wartensee, the castle underwent an extensive period of reconstruction by the architect Nicolas Frick around 1588. In 1697, it suffered a huge fire. The courtyard is enclosed to the south by the long Princess Christina Wing, which was named in memory of visits made by Christina of Saxony, the aunt of Louis XVI and Abbess of Remiremont from 1773 to 1775.
Since 1271 belonging to the bishopric of Basel, the castle served as exile residence of the prince-bishops of Basel from 1527 until 1792. The bishops had been exiled from Basel during the Swiss Reformation in 1529, whereas they were able to keep most of their territories outside the city.
Today, the castle is the seat of the judicial authorities of the Republic and Canton of the Jura. The building’s interior is not open to the public at weekends.
References: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.