A series of aerial photographs which form part of a collection labelled the "historical Google Earth" show the changing face of Wales.
The images, some dating back to 1945, have been made available online by the University of Cambridge.
RAF pilots were asked to capture the bomb-scarred post-war period to the emergence of motorways and new cities.
Prof Martin Millett said the images "let you travel back in time to a Britain which no longer exists".
The Cambridge archaeologist added: "Anyone can go to Google Earth and look at modern satellite imagery - but this is an historical Google Earth.
Instructed by archaeologist JK St Joseph, the university borrowed RAF planes and pilots to take photographs until 1965, when it bought its own Cessna Skymaster.
The plane, based at Cambridge Airport, travelled the length and breadth of Britain to capture high-resolution archaeological detail from the air.
The first 1,500 photographs from an archive numbering almost 500,000 are now available on the university's Digital Library website.
Prof Millett said it had "cherry picked" some of the best and most beautiful photographs, including some very early colour photography.
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Oxford academic Dr Robert Bewley, a world authority on aerial archaeology, described the collection as "internationally important".
He said St Joseph analysed RAF reconnaissance photos during the war and came to realise there was a "huge opportunity" to use similar photos in archaeology and geology.
"He chose former RAF bomber pilot Flt Lt Derek Riley - who had been an archaeologist before the war - to take him on his first trip," he said.
"In those days you could fly where you wanted with few restrictions and that's exactly what they did."
The Department of Geography and Cambridge University Library are exploring potential plans to digitise the entire aerial photography archive.
Photos from the University of Cambridge.