Discovered from the Air

"Were First Spotted When Commercial Aircraft Started To Fly Over The Region Within The Late 1920s. Some Of The Passengers Reported Seeing Some Sort Of Pictures On The Desert Surface Below."

Angel Falls Was Famously Discovered By Jimmy Angel Overflying It In Nov 18 1933 (Though They Were Of Course Known To The Local Pemon Indians)

The Nomination File For The "Antonine Wall" Contains Numerous References (Search On "Aerial") E,G "All The 20 Camps Along The Antonine Wall Have Been Found Through Aerial Survey And Photography. None Is Visible Today." And "Aerial Survey And Photography Shortly After The Second World War Led To The Discovery Of A New Type Of Structure On The Wall: The Fortlet."

Woodhenge In 1925 (Wiki)

"It Was Sighted In 1935 By Prospectors Of The Anglo Iranian Oil Company Who Were Surveying The Region By Airplane"
See Www.Britannica.Com

Kleve-Keeken (20): "The Camp Was First Discovered In 2016 By Aerial Photography." (Nomination File, P. 68)

"The Archaeological Finds From The Burials Of Spina Were Discovered With The Help Of Aerial Photography. Aside From The White Reflective Surfaces Of The Modern Drainage Channels There Appeared In The Photographs A Ghostly Network Of Dark Lines And Light Rectangles, The Former Indicating Richer Vegetation On The Sites Of Ancient Canals. Thus The Layout Of The Ancient Trading Port Was Revealed, Now Miles From The Sea, Due To The Sedimentation Of The Po Delta." (Wiki)
See En.Wikipedia.Org