Subject
Rivers
Bridges
97
Historic buildings
23
Churches
16
Boats
15
Castles & palaces
15
Lakes & ponds
14
Mountains
13
Railroads
13
Waterfalls
12
Piers & wharves
10
Ships
10
Steamboats
9
Valleys
9
Dwellings
8
Abbeys
7
Roads
5
Canals
4
Cathedrals
4
Harbors
4
Towers
4
Universities & colleges
4
Convents
3
Plazas
3
Railroad bridges
3
Meadows
2
Parks
2
Streets
2
Barracks
1
Bays (bodies of water)
1
Catholic churches
1
Hospitals
1
Hotels
1
Islands
1
Mills
1
Railroad stations
1
Schools
1