Collection place
- Okavango delta, Botswana1
- Okayama Prefecture, San'yo region Chugoku region5
- Oke Ila, Ekiti State, Nigeria7
- Okeho, Oyo State, Nigeria4
- Okinawa Island, Okinawa Islands, Ryukyu Islands4
- Okinawa Islands, Ryukyu Islands, Okinawa Prefecture13
- Okinawa Prefecture, Kyushu, Japan32
- Oklahoma49
- Okuzuha village, Eastern Highlands Province, Papua New Guinea111
- Olancha (CDP), Inyo County, California79
- Olberg, Pinal County, Arizona1
- Old Airport area, Grand Canyon, Coconino County20
- Old Cairo, Cairo, Lower Egypt14
- Old Cariboo, Plumas County, California2
- Old Caves Pueblo, Coconino County, Arizona1
- Old Civil Engineering Building (1879-1959), UC Berkeley18
- Old Coast Guard Station, Marin County, California12
- Old Crescent, Clark County, Nevada1
- Old Deerfield, Massachusetts1
- Old Delhi, Delhi State, India2