• 4Winds Tours Ooffers cycling, barging, spring flower, and brewery tours in Holland and France as well as hiking/biking tours in Austria, Ireland, and Denmark.

• Academic Tours Offering cultural and archaelogical tours in Europe.

• Action Factory Offers trips throughout Asia and Europe.

• Adelanta Travel Services Customised group tours of Great Britain (UK) and Western Europe.

• ADVENT Tours Offers a range of subject-based educational tours covering topics such as English, arts, geography, history, languages, and drama.

• Adventures on Skis Offers skiing, biking, hiking, equestrian, and other outdoor vacations in the Alps, Europe, South America, and the Rockies.

• Agency Plus Features Budapest excursions and tours across Hungary.

• Alpin Travel Offers heli-ski and heli-snowboard packages at the Gudauri Caucasus, Republic of Georgia.

• Alpine Adventure Tours Offers cycling tours in France and Italy and cross-country ski tours in Europe.

• Alpine Interface Offers trekking and hiking in the Alps, walking tours in Provence, adventure trekking in Nepal, and sea kayaking in Mexico.

• Alternative Holidays Lesbian and gay travel company offering an array of vacation packages.

• Altius Offers outdoor adventures including horse riding, rock climbing, hiking in the Alps, skiing, and paragliding.

• American Tours & Travel, Inc. Specializes in student group travel throughout the U.S., Mexico, and Europe.

• Anglia Battlefield Tours Offers battlefield and pilgrimage tours in Britain and Europe for schools, colleges, and the general public.

• Any Mountain Tours Offers ski vacation and theme packages throughout the western U.S. and Canada.

• Arc Boutant Offers a summer program in architectural restoration and historic preservation in Europe. Students live and work on-site.

• Archetours, Inc. Architectural tours to destinations in Europe and Japan.

• Art of Travel Offers a variety of international and domestic tours, including guided visits through artistic and architectural landmarks.

• ATG Oxford Offers a range of walking and cycling tours and special interest holidays in Europe and further afield.

• Atlantik Tours Offers circle tours, shore excursions, incentive travel in Iceland and daytours to Greenland.