The CA281 south from Puentenansa follows the Río Nansa upstream. Along the way, a short detour east leads to the attractive hamlet of Tudanca , dominated by the Casona de Tudanca , a white, 18th-century rural mansion. Guided visits last 45 minutes. The house was built by an indiano – that is, someone who had made a fortune in Spain’s Latin American colonies (in this case Peru) and returned. Inside you’ll see all sorts of centuries-old furniture and diverse objects. The house also contains the 18,000-volume library of writer José María de Cossío, to whom it belonged in the 20th century.