Region
Adams National Historical Park (Quincy)
1
Adams National Historical Park (Quincy, Mass.)
2
Africa
3
Africa, Sub-Saharan
1
Africa, West
1
Alamo (San Antonio, Tex.)
1
Alaska
5
Albuquerque
1
Amistad National Recreation Area
1
Amistad National Recreation Area (Tex.)
1
Amsterdam
2
Andersonville
2
Andersonville National Historic Site (Ga.)
2
Arctic regions
1
Arlington
2
Asia
1
Atlanta
1
Austria
3
Baltimore
2
Baroda (Princely State)
1
Berlin
1
Blue Mountain Lake
1
Boston
2
Boston (Mass.)
1
Boulder
2
British Columbia
1
Browning
2
Burgess Shale (B.C.)
1
Cairo
1
California
26
California Coastal National Monument
1
California Coastal National Monument (Calif.)
1
Cambridge
1
Canada
3
Channel Islands National Park
1
Channel Islands National Park (Calif.)
1
Chicago
1
China
1
Cincinnati
1
Colorado
20
Columbia Plateau
1
Connecticut
2
Cooperstown (N.Y.)
1
Copenhagen
1
Corning
1
Cornish (Town)
1
Dayton
4
Dayton (Ohio)
3
Dayton Aviation Heritage National Historical Park (Ohio)
6
Dayton Region
1
more ...