The Sierra de Gredos continues the line of the Sierra de Guadarrama, enclosing Madrid to the north and west. A major mountain range, with peaks in excess of 2500m, Gredos offers the best trekking in central Spain, including high-level routes across the passes, as well as more casual walks around the villages.
By bus, the easiest access to this spectacular region is from Madrid to Arenas de San Pedro, from where you can explore the range, and then move on west into the valley of La Vera in Extremadura. If you have your own transport, you could head into the range south from Ávila along the N502. Stop at any one of the villages on the north side of the range, along the Tormes valley, such as Hoyos del Espino or Navarredonda and explore the spectacular circular walks from there.