The Roman aqueduct of Segovia was built, probably in the 1st century BC, to bring water from the mountains to the hilltop settlement of Segovia. It was a massive feat of engineering as it ran for around 15 km and had to cross a wide valley before it entered the city. It was used to bring water to the town until the 19th century.
Today the aquduct is part of a UNESCO World Heritage Site that also includes the old city and fortifications of Segovia. It is an enormous construction of masonry, 813 m in length, consisting of four straight segments and two superimposed arcades borne by 128 pillars. At the lowest point of the valley, the Aqueduct stands at a height of 28.5 m above ground. The tall arches of the aqueduct bridge are a major tourist attraction.
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.