An ancient Italian city destroyed by Attila the Hun and now hidden underground has been mapped for the first time via infrared photography, officials said.

Infrared aerial photography, combined with 3D reconstruction techniques, has revealed Altinum’s spectacular coastal architecture, complete with bridges, walls, canals, houses and large public buildings, the Italian news agency ANSA reported Saturday.

Writing in the journal Science, Mozzi said the maps show the existence of a complex urban structure and how inhabitants adapted to life on a lagoon.

Attila the Hun’s army destroyed Altinum in 452 AD, with many of the city’s residents fleeing the lagoon islands that later became Venice.