If you're looking for trips that tread lightly near fragile tourist sites and are cognizant of conservation, these five companies could help. Each is noted for eco-travel. Some feature "carbon-neutral" travel (offsetting the pollution caused by the tour itself). Some emphasize putting money back into local communities by hiring locals and paying fairly. All aim to provide tours that gently help preserve what tourists go to see in the first place.

JOURNEYS INTERNATIONAL

Based in: Ann Arbor, Mich.

Tours: Offers 300 eco-trips to 45 countries, including the Galapagos, Africa, Southeast Asia.

Sample tour: "Wild Himalaya," 23 days, Nov. 3-25, $6,995 plus air. Wildlife trip for photographers and naturalists: "a quiet exploration of some of the premier natural areas of Nepal, Bhutan and northeast India."

Winner: Conde Nast Traveler best ecotourism operator, 2005; celebrating its 30th anniversary in business.

Contact: www.journeys-intl.com; 1-800-255-8735.

THE NATURE CONSERVANCY

Based in: Arlington, Va.

Tours: The Nature Conservancy has teamed up with big tour operator Abercrombie & Kent to offer eco-tourist trips to places such as Brazil's Panatal region, Tahiti and Papua New Guinea.

Sample tour: "Nature Conservancy Peru and the Amazon," 12 days, Oct. 11-23, $8,379 plus air. Guided by a Nature Conservancy expert, you travel Peru and end your trip at Machu Picchu.

Contact: Nature Conservancy: www.nature.org; 1-800-628-6860; book travel through www.abercrombiekent.com; 1-800-554-7016.

BUFFALO TOURS

Based in: Hanoi, Vietnam.

Tours: Southeast Asia; custom tours, homestays.

Sample tour: "Cambodia Discovery," 12 days, flexible dates, from $1,713 plus air. Takes you through remote natural areas of Cambodia plus an eco-sensitive tour of Angkor Wat.

Winner: Conde Nast Traveler World Saver Awards 2007 best tour operator.

Contact: www.buffalotours.com.

THE BLUE YONDER

Based in: Kerala, India.

Tours: India off the beaten track, adventure, ecotourism.

Sample tour: "Malabar Mind," 10 days, flexible dates, from $1,600 plus air. Tour includes spice and tea estate tours, hiking in Edakkal caves, country boat cruise, martial arts school visit.

Winner: Conde Nast Traveler World Saver Awards 2007 best tour operator honorable mention.

Contact: www.theblueyonder.com.

ADVENTURESMITH EXPLORATIONS

Based in: Tahoe City, Calif.

Tours: Small ship and adventure tours in places such as the Galapagos and Antarctica.

Sample tour: "Santa Cruz," seven days, flexible dates, from $2,495 (based on double occupancy) plus air. Sail the 90-person Santa Cruz small ship from Quito, Ecuador, to the Galapagos Islands.

Winner: Conde Nast Traveler World Saver Awards 2007 best tour operator honorable mention.

Contact: www.adventuresmithexplorations.com, 1-800-728-2875.