Roman ruins near Lyon may be in danger of destruction, thanks to building crews attempting to put up new houses on top of the remains of an ancient market.

These ruins, discovered by accident when construction workers stumbled upon proof of a thriving ancient economy on the site, have become the subject of the most important archeological find in the last 40 to 50 years. Dubbed a “little Pompeii,” the Roman marketplace appears to have been deserted when civilians were forced to abandon the town because of fires, which ironically preserved the bones of the architecture by destroying the exterior. Archeologists believe that the buried structures might once have included a school of philosophy and an enormous burial ground.

Mosaics of Bacchus, the Roman god of wine, and Thalia, goddess of comedy, are being carefully excavated with a view to exhibit them in Vienne’s museum of Gallo-Roman civilization. The excavation team hopes to complete their restoration before the French government turns the site back to the construction crews who first happened upon it.