"One of the most beautiful and impressive landscapes of Spain," is how the writer and philosopher Miguel de Unamuno described Arribes del Duero, a steep canyon nearly a hundred kilometres long on the Spanish-Portuguese border. To travel this section of the river that the Spanish call Duero and the Portuguese call Douro is to discover one of the most rugged and fascinating natural areas of the Iberian Peninsula. Watched over by vultures and other birds of prey, high granite walls channel the river and make it a constant visual delight. Around the fjords that the Duero forms here, you'll find a real cultural melting pot with border villages marked by their own cuisine, handicrafts and history. There is also a whole range of outdoor activities on offer in this national park area.