A pool (from the Hispanic Arabic albírka, and this from the classical Arabic birkah)[1]​ is a hydraulic construction excavated in the earth, made of brick, rammed earth or masonry in the form of a pond to store water, usually for irrigation.

The term alberca is used in countries like Mexico to refer to swimming pools.

The concept of pool, as an artificial pond, is known in all civilizations, with uses similar to those described for them. It is the intensive use of this type of technical resource for irrigation, as an element of the irrigation network, that gives relevance to the Andalusian pool model.

Even ornamental and leisure use occurred clearly in Greek, Persian, Mesopotamian and, of course, Roman architecture, in whose houses the garden was an important living environment. However, Islamic civilization refined and intensified all these concepts.[2]​.

The application of the name pool to this type of construction dates back to the 13th century.[3] Two centuries later, the first texts are recorded that extend the concept to any building without a roof, even if it is not dedicated to collecting water, which is a second meaning included by the RAE.

Depending on its purpose, several types of swimming pool can be distinguished:

• The irrigation pool. They are usually small ponds, normally the size necessary to irrigate the plots to which they are associated, which receive water from a branch of a commonly used irrigation ditch. In La Alpujarra (Granada) some pools of this type have been dated to times before the 15th century, as in the case of the Alberca de Tímar, next to a medieval route. They are usually linked to areas that were intensively exploited through irrigation in the Middle Ages. These old pools consist of an excavation made in the ground, with a concave interior, so that water loss is difficult, while preventing the pressure from bursting the side walls. Only a small stone wall reinforces the water outlet or , which was closed by a vertical wooden block.[4]​