When archaeologists announced recently they had discovered one of the oldest known ancient Roman military forts in Italy you might have imagined the ruins were unearthed during excavations. Or perhaps you envisaged a Raiders of the Lost Ark-style expedition on which a real-life Indiana Jones uncovered the ruins.

Instead, the large military fort with three-metre thick walls, which was strategically positioned on a hill, was spied from the air.

A LiDAR image shows the outline of structures of the two smaller forts, (A) Grociana piccola and (B) Montedoro.

Increasingly, scientists are using remote-sensing data from satellites and planes to uncover relics from lost worlds.

Claudio Tuniz, an Italian-Australian physicist who lead the discovery team, said the military camp, located in the Trieste area in north-east Italy, near its present-day border with Slovenia, was extensive, with a central camp and two smaller forts.