The Arch of Hadrian is a monumental gateway resembling – in some respects – a Roman triumphal arch. It spanned an ancient road from the center of Athens, to the complex of structures on the eastern side of the city that included the Temple of Olympian Zeus. It has been proposed that the arch was built to celebrate the adventus (arrival) of the Roman Emperor Hadrian and to honor him for his many benefactions to the city, on the occasion of the dedication of the nearby temple complex in 131 or 132 AD.
It is not certain who commissioned the arch, although it is probable that the citizens of Athens or another Greek group were responsible for its construction and design. There were two inscriptions on the arch, facing in opposite directions, naming both Theseus and Hadrian as founders of Athens. While it is clear that the inscriptions honor Hadrian, it is uncertain whether they refer to the city as a whole or to the city in two parts: one old and one new. The early idea, however, that the arch marked the line of the ancient city wall, and thus the division between the old and the new regions of the city, has been shown to be false by further excavation.
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.