Caves and potholes in the El Port geological unit

El Port is a unit of the Serralada Prelitoral that brings together 201 cavities: 106 pits and 95 caves. The total surveyed length is 17435 metres and the maximum depth is 283 metres. The lithologies present are Limestone (105), Dolomite (90) and Conglomerate (6).

Els Ports, a large limestone massif at the confluence of Catalonia, the Valencian Country and Aragon, offer a wild and still little-explored karst. Among the most notable cavities are the Forat de Riu Algars, with 2000 metres of length at Alfara de Carles (el Port), a drop of 43.5 metres and a meandering layout, and a surveyed length of 1190 metres; the Avenc de la Crisi, 148 metres deep, with the largest vertical drop in Catalonia, el Port (Tortosa); and the Avenc dels Mamelons, 167 metres deep at the Mola de Catí (el Port, Tortosa), with an estimated total length of 700 metres.

Other relevant cavities are the Avenc Cp.1, with a drop of 195 metres in the Cova Pintada sector (el Port), with an entrance that leads to subhorizontal conduits, chambers and shafts down to the -179.5 level; the Avenc Cp.3, 74 metres deep in the Cova Pintada sector (el Port), with an entrance shaft of 9 metres, the Via del Mort and the Via de les Sales, and a total length of 665 metres; and the Avenc Cp.6, 283 metres deep on the S slope of Mont Caro (el Port), at the head of the barranc de Cova Pintada, explored by the Espeleo Club Tortosa since 1985.