Alt-Eberstein castle was originally built in 1100 as the primary residence of the Counts of Eberstein, but by the end of the 16th century had been abandoned and much of the castle was torn down to provide materials for other structures. Presently it is a German national monument and a State Palace of Baden-Wuerttemberg.
A spur castle situated on a once-strategic mountain peak, the fortress was constructed as the seat of the Counts of Eberstein perhaps as early as 1100. The oldest part of the castle remaining intact are the ramparts. The first historical mention of the castle occurs in 1197 as Castrum Eberstein. In the second half of the 13th century, the Ebersteins began construction on Castle Neu-Eberstein and the older seat declined in prominence and ultimately fell into disrepair; by 1573, it was uninhabited and thereafter became a quarry used by both the Eberstein descendants and locals. Starting in the 1800s, efforts have been made to preserve the site (which now consists solely of elements of the curtain wall and keep) and it presently one of the State Palaces and Gardens of Baden-Wuerttemberg, housing a restaurant and garden open to tourists.
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.