I fixed the first link to NatGeo, but as noted, the article is for subscribers only.

Here's one everyone should be able to read: Declassified Cold War Satellite Photos Reveal Hundreds of Roman-Era Forts
Once thought to be defensive military bases, the forts may have supported peaceful trade and travel

The program ran from 1960 to 1972, Cold War spy satellites taking a look at the landscape and recording patterns on the ground that are archaeologically important sites.

Using declassified photos from Cold War-era spy satellites, researchers have identified hundreds of previously undiscovered ancient Roman forts in Iraq and Syria. Their findings, published last week in the journal Antiquity, are changing long-held assumptions about the Roman military’s role in the area.

Previously, historians knew about a smaller number of the forts. Dating to between the second and sixth centuries C.E., they were thought to function as defensive military posts. The new research upends these ideas, suggesting the forts were more likely built to support trade and travel.

As lead author Jesse Casana, an archaeologist at Dartmouth, tells CNN’s Mindy Weisberger, they were “places of dynamic cultural exchange and movement of goods and ideas.”

In the 1920s and 30s, French archaeologist Antoine Poidebard discovered 116 of the forts by photographing them from a biplane. These forts appeared to form a defensive wall that ran from north to south along an eastern boundary of the empire. Poidebard thought this wall likely acted as a Roman military barrier against invaders.

More at the link.