Region
Aberdeen Proving Ground (Md.)
1
Absaroka-Beartooth Wilderness (Mont. and Wyo.)
1
Acadia National Park (Me.)
1
Adams National Historical Park (Quincy, Mass.)
1
Afghanistan
4
Africa
17
Africa, North
5
Africa, Sub-Saharan
29
Agua Caliente Band of Cahuilla Indians of the Agua Caliente Indian Reservation, California
1
Akron
2
Alabama
12
Alamo (San Antonio, Tex.)
2
Alaska
59
Alaska Highway Gas Pipeline
1
Albania
2
Albany
1
Alberta
1
Algeria
4
Allegheny National Wild and Scenic River (Pa.)
1
Alpine Lakes Wilderness (Wash.)
1
Amelia
1
America
4
American Canal (Tex.)
1
American Discovery Trail
4
American Memorial Park (Northern Mariana Islands)
3
American Samoa
9
Amur River (China and Russia)
1
Anchorage
1
Andes Region
4
Andorra
2
Angola
1
Ann Arbor
1
Antarctica
1
Appalachian Region
9
Appalachian Trail
1
Arab countries
5
Arabia Mountain National Heritage Area (Ga.)
1
Arches National Park (Utah)
4
Arctic National Wildlife Refuge
2
Arctic National Wildlife Refuge (Alaska)
5
Arctic regions
6
Argentina
10
Arizona
46
Arkansas
10
Arlington
1
Arlington (Tex.)
1
Armenia
1
Armenia (Republic)
1
Ascension
2
Asia
8
more ...