In any large building, especially in the case of a military construction, the supply and storage of water was one of the key aspects for its maintenance and defence. In the case of Torredembarra Castle, water was collected through a system of pipes inside the walls that collected rainwater from the roof, which was then stored under the courtyard.
The Castle’s water tank is a quadrangular structure with a vaulted roof. Given its size, it would have had a capacity of around 70,000 litres of water.
The water was extracted through a stepped gallery excavated in the subsoil, ten metres long and four metres high. At the bottom there are two sliding stone benches, a circular cavity in the paving for collecting impurities from the water, and two pipes connecting the tank with the courtyard. The gallery is reinforced by two arches that support the roof.
Every castle has its legend, and it is said that Torredembarra Castle had a long underground passageway that ran as far as the El Roquer area, specifically Roca Foradada, next to the sea. It was intended for use by the inhabitants of the Castle if they needed to escape. Part of this legend is associated with the gallery that leads to the Castle’s water tank. This feature was in complete ruins until the building was renovated, which is when its true use was discovered.
It should be mentioned that in both Plaça del Castell and some of the streets in the old part of the town there are known to be underground galleries.