The Good Hotel, San Francisco

Photo: Christian Horan

What you'll find: Chic and cheery, the Good Hotel has a clear eco-conscience: Key cards are made from recycled cardboard, chandeliers are fashioned from recycled glass bottles, and most of the 117 rooms have ultragreen toilets.

How you can volunteer: Just pick up the orange phone in the lobby to connect to the nonprofit One Brick, which matches visitors to short-term service gigs. You can roll up your sleeves for a few hours at the San Francisco Food Bank or join a day trip with wetlands conservation group Save the Bay, planting native seedlings along the shores of the Palo Alto Baylands.

What you'll spend: $99 per night on weekdays; $109 on weekends ( )

The Cotton Tree Lodge, Belize

Photo: Raeford Dwyer

What you'll find: Located between two Mayan villages near the Moho River, the Cotton Tree Lodge consists of 11 primarily solar-powered cabanas surrounded by wild fig trees. You can try kayaking, horseback riding, and chocolate-making on the premises, and sample fresh fruits and vegetables from the on-site garden, which is run by the nonprofit Sustainable Harvest International (SHI) ( ).

How you can volunteer: If you don't mind a little mud on your boots, join SHI for daylong projects in the surrounding villages, helping families plant vegetable gardens, build chicken coops, or construct eco-friendly wood-burning stoves.

What you'll spend: $109 to $259 per night ( )

Hale Ho'okipa Inn, Maui, Hawaii

Photo: Ben Pittenger

Hale Ho'okipa Inn, Maui, Hawaii
What you'll find: Owner Cherie Attix has restored a once-crumbling Craftsman-style bungalow (it dates from 1924) into a charming four-room B&B filled with local art and '20s-era antiques. The famed Ho'okipa windsurfing beach is only a 15-minute drive away.

How you can volunteer: Hale Ho'okipa partners with the Leeward Haleakala Watershed Restoration Partnership to replenish the vanishing dryland forests on the slopes of Haleakala mountain. You can get a rugged workout with the group as you hike the mountain, replanting native species.

What you'll spend: $125 to $185 per night ( )


Photo: Courtesy of RockResorts

What you'll find: RockResorts is devoted to down-to-earth comforts (think wooden four-poster beds and rustic detail) and to continuing the conservationist legacy of founder Laurance Rockefeller.

How you can volunteer: During the warmer months at U.S. locations, team up with U.S. Forest Service staffers and other agencies to clear local trails. A trailblazing session will save you up to 30 percent off one night's stay. In St. Lucia, help local farmers build fences and maintain gardens.

What you'll spend: Summer rates start at $139 ( )

Find the volunteer vacation that's right for you