The town of Vidin is situated on the bank of the Danube, in the most northwest corner of Bulgaria, 199km northwest of Sofia. One of the most marvellous cities in the country, Vidin was inhabited by Celts, Romans, and Byzantines, but it was under the Bulgarian Tsars and their Ottoman conquerors that the most frenzied fortress building took place. Such a showpiece is the 13th century fortress of Baba Vida - the biggest historical site of Vidin and the best preserved medieval fortress in the country. Other places of interest in the old town are the ethnographic museum, the 17th century Church of St Petka, the Church of St Panteleimon, the synagogue, and the Vidin fortified system.