Ruse and historically also known as Rustchuk, is the fifth largest city in Bulgaria. Ruse is located in the northeastern part of the country, on the right bank of the Danube, opposite the Romanian city of Giurgiu, approximately 75 km (47 mi) south of Bucharest, 200 km (124 mi) from the Bulgarian Black Sea Coast and 300 km (186 mi) from the capital Sofia. It is the most significant Bulgarian river port, serving an important part of the international trade of the country. Ruse is known for its 19th- and 20th-century Neo-Baroque and Neo-Rococo architecture, which attracts many tourists. It is often called the Little Vienna. The Ruse-Giurgiu Friendship Bridge, until 14 June 2013 the only one in the shared Bulgarian-Romanian section of the Danube, crosses the river here. The legend for the city claims, that the name Ruse comes from the name of a female founder of the city, whose name was Rusa, meaning "blond hair". In the 13th and 14th centuries, during the time of the Second Bulgarian Empire, a fortified settlement called Rusi, first mentioned in 1380, emerged near the ruins of the earlier Roman town. Scholars suggest that the city on the river bank derived its present name from the Cherven fortress, meaning red, through the root rous, which is present in many Slavic languages. Ruse is located on the right bank of the Danube, which is the high bank, having two underwater terraces and three river terraces. The average altitude is 45.5 m (149.28 ft) AMSL. The urban area is an approximately 11-km ellipse running along the river. The city extends from the land-connected Matey island and the mouth of Rusenski Lom on the west to Srabcheto hill on the east. During the 20th century, the west end of the city was significantly modified by moving the mouth of Rusenski Lom to the west, as well as by moving the bank itself with its fairway considerably to the north. Sarabair hill is to the south of the city and is 159 m (521.65 ft) high. TheRousse TV Tower is built there on the remains of Leventtabia, a former Turkish fortification.