Mission Santa Catalina de Guale on St. Catherines Island has been excavated; it is the only mission site of The Georgia Martyrs whose location is known.  Upon completion of the excavation, the site was covered with earth to protect the site, and the location of the site is not publicized to discourage non-authorized digging.
     David Hurst Thomas, archaeologist and anthropologist, explains in the film, St. Catherines: an Island in Time, how the burning of the mission hardened the mud of the walls like a piece of pottery in a kiln.  The magnetic particles in the mud were aligned towards magnetic north, allowing magnetometers, a tool of modern archaeology, to detect the preserved and buried walls. The mission was first burned in 1597 in the Guale Indian uprising and later in 1680 by the British.