Ribera del Algars

The area surrounding the village of Lledó from this point belongs to the municipal territories of Arnes and Horta de San Juan (the Terra Alta). Flows u To the south, the great stone wall of the Puertos de Beceite massif dominates, and in the valley, and Aragon the small hydrographic basin of the Algars River. Divisori

This river is a tributary of the Matarraña River, to which it contributes one sixth of its flow, which subsequently reaches the Ebro. It flows for about 70 kilo- metres from its source, at about 1,100 m. altitude in la Paridora (the Puertos de Beceite massif and Arnes), to the hermitage of Nuestra Señora de dos Aguas (Nonaspe). It runs along the boundary of the co- marca of the Terra Alta and the Matarraña, marking the border between Catalonia and Aragon as established by the Cortes de Cervera in 1359.

The Algars, which in Arabic means 'the cave', takes its name from the hamlet of l'Algars, attached to Batea and currently uninhabited. Along its course it is known as 'el algás', 'lo gas' or 'lo riu del gas'.

It is a rain-fed river and is therefore subject to seasonal variations. It can experience spectacular floods, mainly in autumn, and marked droughts, principally in July and Augus- t. Near its source lies one of the most interesting and abundant underground rivers in the Puertos de Beceite massif.

The Ribera del Algars stands out as a place of great scenic and biological value. The right bank of the river (the Catalan side) has been declared a Partial Nature Reserve due to the existence of an important population of otters (Lutra lutra).