Festival of San Blas de Gradefes Activity · Gradefes, Tierras de León, León Image of Gradefes, not of the place itself. 3 February is the most notable date in the municipality along with the comarca fair of Rueda, held on the second Sunday of August, in a municipal district that brings together numerous villages of the Esla riverbank. Photo: Simon Burchell (CC BY-SA 4.0) What to see and do in Gradefes