Three metre-wide canal which about sixty metres long. It is in the open air, through which a sheet of clear water passes. The box is flat and is built with solid brick. When it passes under the mine house it is channeled, with a semicircular vault of two rows of solid brick. The arrow is 2.2 m. The access is barred by a wrought iron bar grid, which incorporates a locked door. At the mouth of the outlet there is a tombstone, in very poor condition, which cites the purpose for which these waters were intended, as well as the date of construction. There is a second illegible inscription quoting the date 1822. On each side of the headstone there is a rail of iron pipes, which had formerly been balusters. Above the headstone there is a circular pediment. Just above the canal, and about 10 metres from the mouth, we find La Mina House. This small building has the following dimensions: 11 m of main façade and 8.5 m of depth. It consists of a ground-floor body, with a gable roof of Arabic tiles, where the access door is, and another two-storey building, which was been extended with a third floor during the last renovation (1993). The façade of the first body is symmetrical, with a thin arched portal and two windows, one on each side, with the corresponding wrought iron grille. Above the door there is a shield which says "JUNTA DIRECTIVA DE AGUAS DE LA ACEQUIA CONDAL Y SUS MINAS. BARCELONA". The top consists of a powerful cornice following the slope of the exposed brick roof. The other body has a plinth, one window per floor, offset from the axis of symmetry, framed with exposed brick and a segmental arch. The corners are also made of exposed brick imitating ashlar. The third floor has a light wood and glass enclosure and a large sheet metal overhang.

The activity centre has been built behind this building, with a usable terrace. From this building you can see and access the mine through the underground floor, which is illuminated.

During the Roman period, the city of Barcelona was supplied with water by means of three aqueducts, one of which took the waters of the Besòs through a dam and followed the layout of the later Rec Comtal, except for its final part, which in height entered the city through the Roman tower of the Archdeacon's house. Used during the High and Low Empire, it fell into decline in the 8th and 9th centuries, when it was replaced by other forms of collection and supply.

Throughout the early years of the Middle Ages, the old water conduit systems remained abandoned and were often considered as just another element of the landscape. On the other hand, the county initiative on the process of irrigating land that was carried out by the farming communities throughout the 9th and 10th centuries was almost non-existent.

Although the rec comtal does not appear in the documentation until the end of the 11th century (1075), this canal was already known and used before the year 1000. The aim of the works of Count Mir (954-966) in restoring the ancient Roman water supply channels in the city was, above all, the development of milling and other artisanal activities that developed in the plan of Barcelona.

Initially, the river took the waters of the Besòs through a lock made of stones and logs. In 1457 it was decided to build a more solid one made of mortar.

The economic and even political importance of irrigation has been evident since the beginning of the Middle Ages, and the control of the Counts of Barcelona over its waters and their uses was consolidated throughout the period feudal.

During the Middle Ages, El Rec was part of the royal heritage and was administered by the mayor. From the 14th century onwards, the figure of water marshal and administrator of the royal mills of the city and territory of Barcelona appears. These positions, however, were abolished by the Nova Planta Decrees of 1714 and their functions came to depend on the intendant.

The continuous droughts that reduced the supply flows in the city of Barcelona caused, since the Middle Ages, different attempts to use the irrigation system for the supply of drinking water in the city. Finally, in 1704, part of its flow was diverted to Barcelona, in order to feed the public fountains.

In 1778, during the reign of Charles III, it was decided to take advantage of the subalpine waters of the Besòs by opening galleries under the riverbed and setting up the Mina de Montcada, which with a length of 1430 metres, 2 in width and 2 in height ended in the Reixagó or La Mina House. However, the construction of this new complex was promoted by private initiative, under the direction of the Royal Intendant (Juan Felipe de Castaños). To control the works, a board was created made up of representatives of Real Patrimoni, Barcelona City Council and the owners of mills and irrigated land that used their water. The project was in charge of the engineer Josep Subirats and architects Joan Soler and Josep Mas i Vila.

The new construction was crowned by a tombstone with the following legend "with the object of permanent supply, with notable utility of the public at the expense of the Royal Erafio of the City of Barcelona, and of those interested, mills and land irrigation in the reign of His Majesty Carlos III, designed and built by the illustrious intendant Baron de la Linde".

The mine was subject to several extensions: 1822 (Liberal Triennium) where the Royal Heritage did not participate in the expenses, 1836, 1839, etc. In 1839, according to a document from the Cultural Foundation, a tombstone (today illegible) was placed with the following legend: "At the expense of the excellent City Council of the City of Barcelona, of the irrigating owners who have the right to the use of the waters of this mine, and of the owners and participants of the mill, except the Real Patrimonio, 144 rods were built in 1822, and in 1838 and 1839, 333 rods in total".

The mine, a construction made of masonry on the walls and brick on the vault, had two main branches, one started in the Ripoll river, and the other, the most important one, in the Besòs, in front of the Bonet Tower, and crossed Montcada through the underground to Reixagó. Along its route, a series of log wells connected the tunnel to the surface. At this point the water was separated between the Barcelona City Council and the irrigators and owners of the mills.

In 1825, the low mine was built, consisting of 10 kilometres in length, which originated in the Reixagó, headed towards Barcelona, passed through the right side of the Eixample and ended in El Repartirador de Jesús, from where it was distributed in the lower part of the city (Canaletes, Portal de l'Àngel, Porta Ferrissa, etc.).

In the 19th century, and as a result of the prolonged droughts that reduced the flow of the Rec, and caused serious harm to the population, the Barcelona City Council built, near the Besòs, a plant for capturing and treating underground flows. This is the group of buildings of the Montcada wells, built in 1879 according to a project by Barcelona's municipal architect Antoni Rovira i Trias.