Ever since ecotourism took off in the early 1990s, European travelers have helped to spread the movement across the savannas of Africa and the jungles of Central America. Today they’re starting to look closer to home, and with good reason. Some of the most sustainable lodges on the planet are rooted in Old World ways. Take, for instance, Hotel Posada del Valle, a 12-bedroom, 19th-century farmhouse in northern Spain. Located on the remote Asturias coast near the steep mountains of Picos de Europa National Park, Posada sits at the center of one of southern Europe’s last wildlife strongholds. Brown bears still roam the forests, wolves hunt in the fields, and golden eagles soar the thermals. More than a dozen treks begin nearby, ranging from countryside strolls to 7,200-foot summits. When not exploring by foot (or canoe, mountain bike, or horseback), you can visit Posada’s rustic stone-and-wood dining room for organic farm fare—grown on the premises, of course (doubles from $90; posadadelvalle.com).