Embalses de Leurtza Nature · Urroz, Baztan-Bidasoa, Navarra The Leurtza reservoir system, shared with Beintza-Labaien, consists of two gravity dams built in 1920 for hydroelectric power generation, with a difference in elevation of more than 250 meters between them. construidos en 1920 Photo: Txo (CC0) What to see and do in Urroz