I've been many times is Lisbon, I've visited the main and most famous attractions but there are a few not so famous places that I'd like to visit, Mãe d'Água reservoir is one of them. This card from there was sent by Zé.
Moving around Lisbon, one can’t help but notice the massive 18th century aqueduct that runs for 19 kilometers throughout the city. Yet, what many people do not know, the aqueduct feeds into a beautifully designed reservoir known as the Mãe d’Água (Mother of Water).
Foto: Jorge Diniz
Located in the heart of the city, in front of the Amoreira Gardens, is the entrance to this “temple of water.” Completed in 1834, the facility was the key water reservoir for Lisbon. Modern technology has rendered the reservoir obsolete, yet the beauty of Mãe d’Àgua is now open to the public.
During the day, visitors can meander the cavernous structure covered in marble and supported by massive columns. Its mesmerizing transparent water is 7.5 meters deep and is 5500 cubic meters in volume. Mãe d’Àgua is fed through a waterfall fountain on the far wall, which is actually the ending point of the exterior aqueduct. Stairs allow visitors to climb to the top of the fountain for an extraordinary view of the facility. A further climb leads to a panoramic terrace on the roof for equally extraordinary views of Lisbon. - in: http://portugalconfidential.com/mae-dagua-a-hidden-water-temple-in-lisbon/