Late in the summer of 1658, legend has it that an ominous-looking ship sailed into Lynn Harbor. It was painted black and bore no markings or a flag. The locals expected a raid by pirates. Instead, they watched as four of the pirates loaded a chest onto a small boat and rowed up the Saugus River. Eventually, British soldiers learned where the pirates were hiding and raided their camp. Three of them were caught and hung, but a fourth, Thomas Veal, escaped into the forest, taking the hoard of silver with him. Veal reportedly hid in the cave now known as Dungeon Rock.
Then in 1852, Hiram Marble purchased the five acres of land around the cave after hearing the legends of the lost pirate treasure. Marble was part of the Spiritualist movement, believing he could communicate with the ghost of the pirate Thomas Veal and discover the location of the hidden treasure.