Agricultural landscape of Castelnou Nature · Castelnou, Bajo Martín, Teruel Image of Castelnou, not of the place itself. Castelnou is the last town in the Bajo Martín along the course of the river Martín towards its mouth on the Ebro, situated on a steep ravine right on the boundary between Teruel and Zaragoza. The landscape, of a steppe character and listed under the Natura 2000 network, is home to birds such as the stone curlew, the black-bellied sandgrouse and Dupont's lark, and coexists with olive-oil crops from the Bajo Aragón and Calanda peach orchards. Photo: Jaguimera (CC BY 3.0) What to see and do in Castelnou