Baron of Mauá International Bridge, International railway bridge at Brazil-Uruguay border.

The Baron of Mauá International Bridge is a 2,113-metre road and railway bridge over the Jaguarão River linking Jaguarão, Brazil, and Río Branco, Uruguay. Its central section has a double-gauge railway track flanked by two three-metre vehicle lanes, with pedestrian walkways along the sides. The structure has 85 arches and 2,046 piles, and four towers crowned with muslera tiles.

Built between 1927 and 1930 under a 1918 treaty between Brazil and Uruguay settling a war debt, the bridge was inaugurated in 1930 and was then the longest in South America. The Uruguayan side was listed in 1977 and the Brazilian side in 2011; it became the first binational asset protected by IPHAN and the first cultural heritage of Mercosur.

The bridge honours Irineu Evangelista de Souza, Baron and later Viscount of Mauá, a 19th-century businessman and banker who operated in both Brazil and Uruguay. Until the state railway company AFE stopped carrying passengers, trains ran across to Jaguarão and returned full of people and bags, a small-scale smuggling route known as the "quileros" on rails.

The crossing connects both cities directly and allows both pedestrians and vehicles to cross. Visitors should know that the bridge sits at the border and border procedures apply.

The bridge was the first binational asset listed by Brazil's IPHAN and is recognised as the first cultural heritage site of Mercosur. Its two halves were listed separately: the Uruguayan side in 1977 and the Brazilian side in 2011.