Not to be confused with the crypt inside Basilique St-Seurin, this archaeological site accessed via a staircase in front of the basilica's main entrance was uncovered in 1910 when archaeologists excavated part of the vast Christian necropolis beneath place des Martyrs et de la Résistance. Descend into its dimly lit depths to admire 4th- to 6th-century tombstones, amphorae and other ancient relics.
Legend says Charlemagne buried many of his loyal knights here, lost in battle at Roncevaux Pass in 778 CE after Basque troops ambushed Charlemagne's army on the Pyrenean mountain pass.
