Griffen castle was built between 1124 and 1146 by order of Bishop Otto of Bamberg. In an 1160 deed, Emperor Friedrich I mentioned Grivena as a Bamberg property.
In 1292 the Carinthian nobleman Count Ulrich von Heunburg with support of Archbishop Konrad IV of Salzburg occupied the fort in an uprising against Albert of Habsburg, the son of King Rudolph I of Germany and Duke Meinhard II. However Ulrich was abandoned by his allies and one year later had to leave the castle. In 1759 Bishop Adam Friedrich sold the Bamberg estates in Carinthia to Maria Theresa of Austria and the castle was incorporated into the Carinthian duchy.
About 1520 a large reconstruction of the castle took place as a protection against the threat posed by the Ottoman forces with a base amounted of about 4000 m², though the Turks never laid siege to Griffen. In 1659 a flash impact destroyed one of the towers and the decay of the castle began. In 1768 a last religious service took place and about 1840 the roofs were torn. In 2000 the preservation of the castle began. A steep footpath leads up the mountain to the ruins.
Within the mountain is the Griffener Tropfsteinhöhle (dripstone cave) with a length of 485m, which was not discovered until the late days of World War II. It is open to public and a natural landmark since 1957.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.