Aqueduct Aguas Librish (literally - "free water aqueduct") is considered one of the most interesting buildings in Lisbon. This impressive size engineering construction is part of a water supply system in Lisbon and crosses the valley of the Alcantara in the north-western part of Lisbon.

The aqueduct consists of 35 arches, of which 21 has a semicircular arch shape, 14 - lancet, the tallest of which - 62 and 33 meters, 7 meters in length. Aqueduct was not injured during the Lisbon earthquake in 1755 precisely because of its design. The length of the aqueduct - 941 meter. Basically, it goes underground and occasionally comes to the surface in the form of grand arcades.

The aqueduct was built during the reign of Juan V, who was known for his love for everything grand and majestic. The appearance of the aqueduct has solved the problem of water shortage in the city, which is particularly acute in the summer. Construction was started in 1731 and the works lasted for decades. He supervised the construction of the Portuguese engineer Manuel de Maya, who later took an active part in the reconstruction of Lisbon after the earthquake in 1755. The water through the aqueduct fell into the tank Mahe Aguas, and then distributed throughout the city.

Until the middle of the XIX century on the aqueduct was inaugurated pedestrian walkway. But after it handled the famous killer Diogo Alves (robbed victims and dumped down), and cases of suicide, a pedestrian passage was closed. Today, the aqueduct is only open for organized groups who agree to tour in advance.