Auch Cathedral of Sainte-Marie (1489–1662) is one of the finest Gothic buildings of southern France. Its chief features are 113 Renaissance choir stalls of carved oak and Renaissance stained-glass windows by Arnaud de Moles. The cathedral’s classical facade dates from the 16th and 17th centuries, and its great organ (17th century) is one of the finest in the world for playing Baroque music. The 18th-century archbishop’s palace, with a 14th-century tower, adjoins the cathedral. Nearby are a museum of art and archaeology and a museum containing the historical archives of the département of Gers, together with a large library and a collection of manuscripts. The prefecture, adjoining the cathedral, was once the palace of the archbishops of Auch.
References:Bomarsund fortress and garrison was built in 1832-1854 by Russian Empire to defence Åland Islands against enemies. British and French fleet attacked against it during the Crimean War in 1854. After a week of fighting the British stormed the remaining fort. Anglo-French forces destroyed it totally after battle. In the Treaty of Paris 1856, the entire Åland Islands were demilitarized, which is a status that has been preserved until this day.
Nowadays there are some ruins left and fortress area is open for visitors.