Billnäs ironworks was founded in 1641 by Carl Billsten. It faced many difficulties during 17th and 18th century. Local peasants destroyed the ironworks already in 1659 because of too heavy taxation. During the Great Wrath Russians occupied and destroyed it again in the 18th century.
Billnäs Ironworks moved to Hisinger family's possession in 1723. Bar hammer workshops with forges and waterwheels, and coal rooms were built to both sides of the rapids in Billnäs Ironworks. Johan Hisinger was especially active in building and developing the Ironworks’ operations. Billnäs manufactured many kind of forge products until 1920, when it was incorporated into Fiskars Corporation (the another ironworks site nearby).
An industrial business ended in Billnäs in the end of the 20th century. Today it’s moved to the use of service industry. Various public events, concerts and exhibitions among others, are organized in the Billnäs Ironworks. In the long run, hotel- and restaurant operations are planned to the area as well as a full renovation of the valuable real estates. The ironworks area is today a well-preserved national heritage. The most valuable building is the great forge from the 17th century.
The Château Comtal (Count’s Castle) is a medieval castle within the Cité of Carcassonne, the largest city in Europe with its city walls still intact. The Château Comtal has a strong claim to be called a 'Cathar Castle'. When the Catholic Crusader army arrived in 1209 they first attacked Raymond-Roger Trencavel's castrum at Bèziers and then moved on to his main stronghold at Carcassonne.
The castle with rectangular shape is separated from the city by a deep ditch and defended by two barbicans. There are six towers curtain walls.
The castle was restored in 1853 by the architect Eugène Viollet-le-Duc. It was added to the UNESCO list of World Heritage Sites in 1997.