Shumen (also spelled Shoumen or Šumen, Bulgarian: Шумен, Turkish: Şumnu), is the tenth largest city in Bulgaria and the administrative and economic capital of Shumen Province. Earliest reports for Shumen fortress date back to the early Iron Age. From the 12th century BC is the first fort, surrounding accessible parts of the area. Archaeological surveys, conducted in 1957, 1961 to 1987, determined the chronological periods, the lifestyle and the livelihood of the inhabitants of the fortress. It had a wall thickness of about two meters, built of rough stones. In the 5th century BC second wall was built in front of the former. In the 2nd century the Romans built a military fortress on the ruins of the Thracian fortifications. The construction of the wall is already bonded to mortar; a tower was constructed above the gate; square tower was built to the west and semicircular to the south. In the 4-5th centuries the entire hill was fortified with a new wall with nine towers. Between the 8th and the 10th century the fort was renovated, for the purpose the Roman wall and towers were used and to the northeast was built a new wall with two towers. The city lies 80 kilometres (50 miles) west of Varna and is built within a cluster of hills, northern outliers of the eastern Balkans, which curve round it on the west and south in the shape of a horse-shoe. A rugged ravine intersects the ground longitudinally within the horse-shoe ridge. From Shumen roads radiate northwards to the Danubian cities of Rousse and Silistra and to Dobruja, southwards to the passes of the Balkans, and eastwards to Varna and Balchik.