Keep scrolling down for answers and more stats ...
1.
Caucasus
Madagascar, Armenia, Sierra Leone, Chad
2.
Andes
Taiwan, Philippines, Czech Republic, Chile
3.
Alps
Leichtenstein, Dominican Republic, Belarus, Sweden
4.
Himalayas
Afghanistan, Nepal, Latvia, Thailand
5.
Atlas
Kenya, Comoros, Algeria, Namibia
6.
Appalachian
France, Liberia, Mexico, Malaysia