Considering the Casa De Sao Tiago in Évora?
A VT member wrote the following comment about visiting Évora:
Aqueduct near St. Anthony's Fort 1 by johnsakura
Due to the lack of water inside the old town city walls, D. Joao III, in the XVI century, order to build the aqueduct. It's 18km (59055 feet) long spreding it's monumental apearence all over town. It's classified has National Monument.