King Pacific Lodge, British Columbia
What Makes It Great
Its spacious rooms have rain forest or water views, and a spa awaits guests after a day of hiking or fishing.
What Makes It Green
Built on a barge moored in a harbor, the lodge is approaching carbon neutrality by using hydro and solar power (604-987-5452; kingpacificlodge.com; doubles, $5,000–$5,800 for three nights).

Ucka Lodge, Istria, Croatia
What Makes It Great
Set in a national park beside the sea, the lodge has cozy handcrafted cabins (385-917-622027; uckalodge.com; doubles, $400 for three nights).
What Makes It Green
The lodge is solar-powered, and all waste is biologically filtered.

Sacha Jungle Lodge, Ecuador
What Makes It Great
At least 60 bird species can be seen on the lodge's 5,000-acre private reserve, where accommodations are cooled by ceiling fans and have covered terraces.
What Makes It Green
The lodge was built with sustainable materials and has protected thousands of acres from development (800-706-2215; sachalodge.com.ec; doubles, $1,380 for three nights).

Badrutt's Palace Hotel, St. Moritz, Switzerland
What Makes It Great
The luxurious rooms have Alpine views, there's a spa, and activities include skiing, golf, tennis, and swimming.
What Makes It Green
A new state-of-the-art heat pump system warms the hotel as well as a nearby school, cutting CO2 emissions by 75 percent (41-81-837-1100; badruttspalace.com; doubles, $710–$1,930).

Sadie Cove, Kachemak Bay State Park, Alaska
What Makes It Great
Tucked in a fjord with whale-, bear-, and bird-watching, its five cabins are a retreat after a day of hiking or kayaking.
What Makes It Green
The cabins run on private hydroelectric and solar energy systems, and water is from a mountain spring (907-235-2350; sadiecove.com; doubles, $700).

Papoose Creek Lodge, Cameron, Montana
What Makes It Great
The lodge's three cabins and five guest rooms are near fly-fishing and canoeing in the Madison River, and horseback riding and hiking in Yellowstone National Park.
What Makes It Green
The cabins are built with reclaimed timber, and the lodge's nonprofit conservation and research arm focuses on ecotourism, sustainable ranching, and wildlife conservation (888-674-3030; papoosecreek.com; doubles, $1,005 for three nights).