Region
Aberdeen Proving Ground (Md.)
1
Abraham Lincoln National Heritage Area (Ill.)
4
Acadia National Park (Me.)
7
Accomack County
3
Adams County
1
Admiralty Island National Monument Wilderness (Alaska)
3
Aegean Islands (Greece and Turkey)
1
Afghanistan
52
Africa
64
Africa South of the Sahara
23
Africa, Central
1
Africa, English-speaking
1
Africa, French-speaking
1
Africa, North
6
Africa, Sub-Saharan
40
Africa, West
1
Agua Caliente Band of Cahuilla Indians of the Agua Caliente Indian Reservation, California
2
Agua Prieta (Sonora)
1
Ak Chin Reservation (Ariz.)
3
Ak-Chin Indian Community
1
Ala Kahakai National Historic Trail (Hawaii)
2
Alabama
28
Alabama Hills (Calif.)
2
Alabama-Coushatta Tribe of Texas
1
Alaska
238
Alaska Maritime National Wildlife Refuge (Alaska)
2
Alaska Peninsula
3
Alaska Peninsula (Alaska)
5
Alaska Peninsula National Wildlife Refuge (Alaska)
1
Albania
15
Alberta
1
Albuquerque
1
Aleutian Islands
2
Alex Diekmann Peak (Mont.)
2
Alexandria
1
Algeria
9
Allegheny National Forest
4
Allegheny Portage Railroad National Historic Site (Pa.)
2
Allegheny River (Pa. and N.Y.)
2
Alpine Lakes Wilderness (Wash.)
8
Alps Region
1
Alsek River
1
Amache
1
Amazon River Region
1
Amazon River Watershed
1
Amchitka Island
1
America
13
American Canal (Tex.)
1
American Discovery Trail
7
American Falls Reservoir
6
more ...