The Águas Livres Aqueduct spans the Alcântara valley in Lisbon with its 35 arches and is nowadays part of the Museu da Água. It is accessible to those interested and offers panoramic views over the Alcântara valley.

It also has an illustrious past because of the Spanish serial killer, Diogo Alves, who from 1836 to 1839 would hide close to the Águas Livres Aqueduct waiting for his victims who would use the aqueduct as a bridge to cross the valley. After robbing them he would throw the bodies from the top of the aqueduct and he is said to have killed 76 victims.