The bridge was started in 1751 and took 42 years to build. Fifty workers were killed during its construction. There is a chamber above the central arch that was used for a variety of purposes, including as a prison. During the 1936-1939 civil war both sides allegedly used the prison as a torture chamber for captured opponents, killing some by throwing them from the windows to the rocks at the bottom of the El Tajo gorge.[citation needed] The chamber is entered through a square building that was once the guard-house. It now contains an exhibition describing the bridge's history and construction.

Both Nationalists and Republicans are claimed to have thrown prisoners from the bridge to their deaths in the canyon during the Spanish Civil War https://en.wikipedia.org/wiki/Puente_Nuevo