The canyons of  Sierra de Guara

The mountain range of the Sierra de Guara, whose highest summit peaks at 2077m, corresponds to the first foothills of the Spanish Pyrenees. Here exists the largest concentration of canyons in Europe.

The majority of the landscapes have a character of karst origin sculpted in the limestone (lapiaz on the surface, canyons, turrets and sculptures of strange shapes). We also find conglomerate which has been dug by water forming very characteristic narrow canyons called “barrancos”.

The formation of the canyons of the Sierra de Guara

To better understand this slow geological phenomenon at the origin of the formation of the Sierra de Guara canyons, we must go back in time and adopt a regional perspective summarized in 3 steps:

1- Around 25 million years ago, the Pyrenees were already formed and erosion had been carrying out its intense work for a long time. Little by little, via the appearance of a river network, transporting gigantic volumes of gravel torn from the reliefs of the Pyrenees, enormous thicknesses of conglomerates mentioned previously were formed.

2- At the beginning of the Miocene (15 million years), more than 3 kilometers of thickness of sediments had accumulated at the foot of the Pyrenees, in the Ebro basin. At that time, this basin was not in direct communication with the sea, so it behaved like a gigantic basin into which sediments coming from the mountain range were dumped. That lasted until the Ebro opened to the sea. Then the rivers did a gigantic job of intense erosion via the creation of a fluvial network conducive to emptying the basin in certain places, as is the case in Sierra de Guara.

3- Today, the rivers of the Sierra de Guara continue to evolve and it is during periods of heavy rain that the work of erosion and river transport increases.

The color of the water in the canyons of Sierra de Guara

One of the main points that attracts the canyons of the Sierra de Guara and which contributes to their international notoriety is the rather unique color of the water. Indeed, the frequent blue-green color of the water in basins and bodies of water is due to the fact that during low water periods (when levels are low), the water carries small volumes of sediment, and cyanophyceous algae proliferate. The latter find here an environment favorable to their development thanks to a limestone bedrock with clean, clear, well-lit water. They are what give the waters this attractive color.

These two phenomena, formation of canyons and incredible water colors, mixed with a favorable Mediterranean climate and lush vegetation have contributed to the development of canyoning activity in this unique region!

In the following pages, we’ll introduce you to some of the best canyons to descend in the area. They are classified by basins because in eachone, there are interesting rivers networks.