Elvas, Aqueduto da Amoreira, HWW

Opened year 1498.
The aqueduct has a length of 7,054 metres (23,143 ft) from its spring in the Serra do Bispo until the Chafariz do Jardim, and another 450 metres (1,480 ft) to the town fountain.[1][2] Its track includes 1,367 metres (4,485 ft) subterranean segments, to a maximum altitude of 4,049 metres (13,284 ft) above sea level, while 1,683 metres (5,522 ft) include arcade segments.[1]

More info : en.wikipedia.org/wiki/Amoreira_Aqueduct