Reservatório da Patriarcal
Reservatório da Patriarcal is underneath jardim do Príncipe Real (its entrance can be found in the middle of this garden) and it’s constituted by an impressive underground cistern with vaulted ceilings which resemble a cathedral. Reservatório da Patriarcal is divided into three galleries that lead to galeria do Loreto, rua da Alegria and rua de São Marçal. Nowadays, it is possible to visit the cistern and walk through a 400 meters gallery that connects the reservoir to galeria do Loreto and leads to an exit in São Pedro de Alcântara garden-viewpoint. Reservatório da Patriarcal closes on Sundays.
Reservatório da Patriarcal was built to supply the downtown with water (that came from Águas Livres aqueduct). It is formed by 31 pillars, each with 29 feet tall, forming an octagon that makes it capable to store up to 880 cubic meters of water. It was designed by French engineer Charles Mary, having been finished in 1894. It started to be used immediately and continued to supply water to the town until 1949, the year it was deactivated. In 1994, thanks to a rehabilitation plan, it opened to host exhibits and shows. Todays, it’s one of the most surprising secrets of Lisbon and it accepts visits by groups up to 40 people.