WHERE Zalabi Valley, Andalucía, Spain

HOW MUCH From $80 for a double

MORE tíotobas.com

GETTING THERE Pedal a mountain bike with H&I Adventures through six days of thigh-burning climbs and rollicking singletrack descents circumnavigating Spain's Sierra Nevada. After stunning views of glaciated peaks and a quick visit to the ornate Moorish fortress turned Italian Renaissance castle La Calahorra, arrive at Tío Tobas cave hotel in Zalabi Valley. Or just drive an hour east from Granada.

BEST MOMENT Lunch. We had fresh bread from a wood-fired oven, a hearty garlic-infused potato, peasant stew with vegetables and five kinds of meat, and custardy bread pudding, among many, many other dishes, all accompanied by local wine. Nearly every dish--served family style--featured fragrant, grass-green local olive oil. Food kept arriving even after we begged the servers to stop.

FAVORITE CHARACTER Zalabi Valley mayor Manuel Aranda, a portly, chain-smoking former insurance agent who saw the potential of cave-hotel tourism. He opened Tío Tobas with one room in 1994 and has since expanded it into a 19-room resort, with hiking, cross-country skiing, archery, horseback riding, and a bicycle contraption you pedal on old rails. Gruff but beloved, he's obsessed with putting Zalabi Valley on the map.

LOCAL LORE Until recently, cave living was considered something reserved for Gypsies and squatters. Now upscale Granadans own vacation caves, and the mayor lives in one full-time. 

WHAT'S GREEN Its 19 cave rooms, some more than 150 years old, require almost no heating or cooling. If needed, fireplaces burn scrap olive branches and plantation poplar. Tío Tobas employs only locals, and nearly all its food is locally produced. Cave decor is recycled--stone tiles, bricks, wooden doors, and benches. 

WHAT'S NOT GREEN Petrol-powered recreation and cigarette smoke. 

PLANET SAVING OPPORTUNITIES Donate to or volunteer with Ecologists in Action, a coalition of 300-plus groups working on environmental advocacy and education campaigns around Spain. They offer various "voluntourism" outings, including an anti-fracking bike ride, and are active in Andalucia.