Cordoba, Spain, is a modern city home to more than 300,000 but its roots date back thousands of years. Now, using light detection and ranging technology, LiDAR for short, researchers have created three-dimensional maps of the region that digitally reconstruct three cities built on top of one another over the course of more than 2,000 years.
Researchers reanalyzed relief maps obtained by a 2016 LiDAR flight conducted by the National Geographic Institute in order to understand how the southcentral Spanish city has evolved through the ages. Despite a lack of archaeological information – most of the ruins are buried beneath new buildings – they were able to digitally reconstruct the geomorphology of the area where Cordoba is now located before it was covered with buildings.
More than 2,000 years ago, Cordoba was once home to an Iberian city located on a hill now named Quemados. There is also evidence suggesting that during the Late Bronze Age it was occupied by a society characterized by metallurgy. Sometime around 169 BC, Roman military leader Marcus Claudius Marcellus built a new city located 500 meters (1,640 feet) to the west. Records indicate that the city was established so that Rome could hold control over the middle valley of the Guadalquivir River and the rich mines located in the city’s mountains, but most remains from this time period are “extremely deep and buried under an enormous amount of silty clay” likely due to a massive flooding event. In Roman and medieval times, the city eventually spread over the old riverbed where the residents built high foundations and fortifications to avoid flooding.
Images show how the two settlements were strategically located next to a riverbed, which throughout the last millennium has gradually migrated to the south.
“In recent years, numerous discoveries have been made in Spain, especially in non-built-up areas located outside urban enclaves. Less attention, however, has been paid to the use of this geographical information in historic cities,” wrote the authors in Geosciences, adding that their work demonstrates the usefulness of LiDAR in analyzing ancient urban structures that are buried meters deep in current historic cities.