Giants' graves, or Tomba dei giganti, are megalithic gallery graves that were used as public tombs during the Bronze Age. The tombs are made of a central stele, a stone or wooden slab, which has a hole cut into it that functions as the entrance. Walls extend from the door and form an interior corridor grave. Originally, the interior would have been covered.

So far, 321 such monuments have been discovered in Sardinia, including the one at Coddu Vecchiu. The massive gravestones were built by the Nuragic civilization, which existed in Sardinia from the second millennium BCE. to the second century CE. Despite the imaginative name, the sites were not the burial site of any giant; they were giant community burial chambers.

Though we know the tombs had a funerary purpose, more questions remain. Little is known about the rituals or traditional beliefs that motivated their construction. Were they mass graves? Were they built to facilitate the journey into the afterlife? Since their existence has yet to be justified by scientific research, they have been credited to the supernatural, which has only increased their mystery. For example, it is widely believed that positive energy infuses the air surrounding a Giants' Tomb and provides spiritual rejuvenation.

Legend also claims that yes, indeed, these were the tombs of powerful giants. It is the enormity of the slabs that feeds that theory; the largest is over 100 feet tall.

In part because of the presence of these imposing monuments, several journalists and researchers have argued that Sardinia is the site of the lost Atlantis. In 2002, journalist Sergio Frau published a book, "The Pillars of Hercules," arguing that the Nuragic civilization was destroyed suddenly by a tsunami, just like Atlantis. A recent exhibition at UNESCO was devoted to Frau's theory, Sardinian monuments, and the "imposing vanished civilisation of the Nuraghes." After all, all that remains of that lost world are enigmatic stone remnants.