Piedra (Spain)

Piedra
The Piedra flowing through the Monasterio de Piedra area
The watershed of the Piedra within the Ebro basin.
Native name	Río Piedra (Spanish)
Location
Country	Spain
Region	Castile-La Mancha, Aragón
District	province of Guadalajara, province of Zaragoza
City	Campillo de Dueñas, Cimballa, Nuévalos, Carenas, Castejón de las Armas
Physical characteristics
Source	Campillo de Dueñas
• location	province of Guadalajara, Castile-La Mancha, Spain
• coordinates	40°49′59″N 1°39′18″W / 40.833°N 1.655°W / 40.833; -1.655
• elevation	1,195 m (3,921 ft)
Mouth	Castejón de las Armas
• location	province of Zaragoza, Aragón, Spain
• coordinates	41°19′08″N 1°48′36″W / 41.319°N 1.810°W / 41.319; -1.810
• elevation	590 m (1,940 ft)
Length	76 km (47 mi)
Discharge
• average	1.22 m3/s (43 cu ft/s)
Basin features
Progression	Jalón→ Ebro→ Balearic Sea
Tributaries
• left	Mesa River
• right	Ortiz, Munebraga
River system	Ebro

The Piedra (Spanish: Río Piedra) is a river in the Iberian System area, Spain. It is a tributary of the river Jalón. The waters have a high concentration of calcium carbonate^[1] which is deposited on plant life near the source, giving the river its name Río Piedra, which means 'stone river' in English.

The population of the endangered European freshwater crayfish in the river and its tributaries has practically disappeared owing to the introduction of the North American signal crayfish (Pacifastacus leniusculus).^[2]