The ruins of ancient Sparta lie north of the modern city. It was a prominent city-state in Laconia in ancient Greece. Around 650 BC, it rose to become the dominant military land-power in ancient Greece.
Given its military pre-eminence, Sparta was recognized as the leading force of the unified Greek military during the Greco-Persian Wars, in rivalry with the rising naval power of Athens. Sparta was the principal enemy of Athens during the Peloponnesian War (431–404 BC), from which it emerged victorious after the Battle of Aegospotami. The decisive Battle of Leuctra against Thebes in 371 BC ended the Spartan hegemony, although the city-state maintained its political independence until its forced integration into the Achaean League in 192 BC. The city nevertheless recovered much autonomy after the Roman conquest of Greece in 146 BC and prospered during the Roman Empire, as its antiquarian customs attracted many Roman tourists. However, Sparta was sacked in 396 AD by the Visigothic king Alaric, and underwent a long period of decline, especially in the Middle Ages, when many of its citizens moved to Mystras.
Entering by the South Gate of the Acropolis, known as Lakedaemonia, there is the Rotunda, the Theatre and the Temple of Athena Chalkioikos to the West. Exiting the Acropolis by the North Gate there are the remains of the earliest ancient walls, the Heroon and the Altar of Lycourgos, whereas to the East there is the Sanctuary of Artemis Orthia. To the North is the Monastic Church of Osios Nikonas (10th century).
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.