Tarn (river) a mean flow of approximately . The Millau Viaduct spans the valley of the Tarn near Millau, and is now one of the area's most popular attractions. The tributaries of the Tarn include: The Tarn separates the Narbonne and Aquitaine basins. The Tarn passes through the following departments and towns: The Millau Viaduct, the tallest bridge in the world, carrying the A75 autoroute across the Tarn Gorge near Millau, opened in December 2004. The Tarn is famous for its brutal floodings, which are the most dangerous in Europe along with the Danube. The flooding of March 1930 saw the Tarn
Bridge of the Americas the bottleneck of, and reduce traffic congestion on, the Bridge of the Americas. The bridge is a cantilever design where the suspended span is a tied arch. The bridge has a total length of 1,654 m (5,425 ft) in 14 spans, abutment to abutment. The main span measures and the tied arch (the center part of the main span) is . The highest point of the bridge is above mean sea level; the clearance under the main span is at high tide. Ships must cross under this bridge when traversing the Panama Canal, and are subject to this height restriction.