Arta is a city in northwestern Greece and capital of the regional unit of Arta, which is part of Epirus region. The city was known in ancient tim…Arta is a city in northwestern Greece and capital of the regional unit of Arta, which is part of Epirus region. The city was known in ancient times as Ambracia. Arta is known for the medieval bridge over the Arachthos River, as well as for its ancient sites from the era of Pyrrhus of Epirus and its well-preserved 13th-century castle. Arta's Byzantine history is reflected in its many Byzantine churches; perhaps the best known is the Panagia Paregoretissa, built about 1290 by Despot Nikephoros I Komnenos Doukas.