President Costa e Silva Bridge, commonly known as the Rio-Niteroi Bridge, is a box girder bridge located at Guanabara Bay, in the State of Rio de Janeiro in Brazil. It connects the cities of Rio de Janeiro and the municipality of Niterói. It is currently the longest prestressed concrete bridge in the southern hemisphere, and the sixth longest in the World. From its completion in 1974 until 1985 it was the world's second-longest bridge, second only to Lake Pontchartrain Causeway.
The concept of its design dates back to 1875. In order to connect the two neighbouring towns, separated by the Guanabara Bay or an inland journey of more than 100 kilometers (62 mi), passing through the city of Mage. At the time it was intended to build a bridge and subsequently a tunnel.
In 1963 a working group was created to study a bridge-building project. On December 29, 1965, an executive committee was formed to take care of the final project of building a bridge.
The President Costa e Silva signed a decree on August 23 of 1968 Authorizing the project for the bridge, designed by Mario Andreazza Then Minister of Transport, under the management of whom the bridge was begun and completed.