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.
Medvedgrad is a medieval fortified town located on the south slopes of Medvednica mountain, approximately halfway from the Croatian capital Zagreb to the mountain top Sljeme. For defensive purposes it was built on a hill, Mali Plazur, that is a spur of the main ridge of the mountain that overlooks the city. On a clear day the castle can be seen from far away, especially the high main tower. Below the main tower of the castle is Oltar Domovine (Altar of the homeland) which is dedicated to Croatian soldiers killed in the Croatian War of Independence.
In 1242, Mongols invaded Zagreb. The city was destroyed and burned to the ground. This prompted the building of Medvedgrad. Encouraged by Pope Innocent IV, Philip Türje, bishop of Zagreb, built the fortress between 1249 and 1254. It was later owned by bans of Slavonia. Notable Croatian and Hungarian poet and ban of Slavonia Janus Pannonius (Ivan Česmički) died in the Medvedgrad castle on March 27, 1472.
The last Medvedgrad owners and inhabitants was the Gregorijanec family, who gained possession of Medvedgrad in 1562. In 1574, the walls of Medvedgrad were reinforced, but after the 1590 Neulengbach earthquake, the fortress was heavily damaged and ultimately abandoned. It remained in ruins until the late 20th century, when it was partly restored and now offers a panoramic view of the city from an altitude of over 500 meters.