Founded in 510 BC by the Greeks, previously known as Mesembria, Nessebar is nowadays a major tourist attraction on the Black Sea coast. The ancient part of the town is situated on a peninsula connected to the mainland by a narrow man-made isthmus. In 1956 the town was proclaimed an architectural and archeological reserve. The remnants of an antique fortified wall with a gate dating from III-IV century, the churches from V-VI century and the ones dating from the medieval period (X-XIV century), which are fine works of the medieval Bulgarian and Byzantine architecture, the 60 houses of the revival period, give the town unique appearance and atmosphere. Its abundance of historic buildings prompted UNESCO to include Nesebar in its list of World Heritage Sites in 1983.