A short distance away from Madrid, the rugged, weathered peaks of the Sierra de Gredos serve as a refreshingly cool retreat from the heat and bustle of the capital. Ancient hilltop towns and cottages dot the tortured landscape of alpine meadows, tumbled boulders, and thick scrub brush. Clustered around this rugged range are several DOs, most notably Mentrida and Viños de Madrid, best known for producing reliably inexpensive and simple country wines to slake the capital’s thirst. But viticulture in Spain is ancient and tenacious, so the adventurous can also find scattered vineyards situated in the most inaccessible places, including rockfalls and natural amphitheaters high up in the most remote parts of the backcountry.