Vidin (Видин, ˈvidin; Romanian: Diiu) is a port city on the southern bank of the Danube in north-western Bulgaria. It is close to the borders with Romania and Serbia, and is also the administrative centre of Vidin Province, as well as of the Metropolitan of Vidin (since 870). An agricultural and trade centre, Vidin has a fertile hinterland renowned for its wines. The name is archaically spelled as Widdin in English. Old name Dunonia itself meant "fortified hill" in Celtic with the typically dun found frequently in Celtic place names. Vidin is the westernmost important Bulgarian Danube port and is situated on one of the southernmost sections of the river. The New Europe Bridge, completed in 2013, connects Vidin to the Romanian town of Calafat on the opposite bank of the Danube. Previously, a ferry located from the town was in use for that purpose. Vidin has a humid subtropical climate close to a temperate continental climate, from which it is shifting further and further away due to global warming. In the winter months, inversions are very common. The average annual temperature is . Vidin emerged at the place of an old Celtic settlement known as Dunonia. The settlement evolved into a Roman fortified town called Bononia. The town grew into one of the important centres of the province of Upper Moesia, encompassing the territory of modern north-western Bulgaria and eastern Serbia. When Slavs settled in the area, they called the town Badin or Bdin, where the modern name comes from. Similarly, Anna Komnene refers to it as Vidynē (Βιδύνη) in the Alexiad. Vidin's main landmark, the Baba Vida fortress, was built in the period from the 10th to the 14th century. In the Middle Ages Vidin used to be an important Bulgarian city, a bishop seat and capital of a large province. Between 971 and 976 the town was the center of Samuil's possessions while his brothers ruled to the south. In 1003 Vidin was seized by Basil II after an eight-month siege because of the betrayal of the local bishop.