Europe

ACE Cycling and Mountaineering Center - Cycling, hiking and mountaineering guided tours in the Balkans. Based in Serbia and Montenegro.
www.ace-adventurecentre.com/

Arctic Discovery - Activity holidays in Lapland and northern Sweden feature dog-sleighing, snowmobiling, heli-skiing, cross-country skiing, snowboarding and ice fishing.
www.arcticdiscovery.com/

Top Sport Travel - Specializes in alpine skiing, mountain climbing, and trekking in Russia and other European countries. Description of services, contact information. [English, Russian]
www.slope.ru/