Despite decades of archaeological digging, one thing in Mexico City’s ruins has proved impossible to find: the tombs of ancient Aztec emperors. Now a recent discovery in the ruins of the city’s Templo Mayor just off its central plaza may be what finally unlocks the shrine built for former kings. A team of archeologists found a large stone box at the base of the temple (which would have once stood as a 15-story pyramid before the Spanish destroyed it) and so far have found a jaguar decorated as a warrior, the remains of a young boy dressed as a war god, and knives decorated with mother of pearl and other stones. Only 10 percent of the box has been explored, as a large amount of coral is blocking researchers. But according to Mexico specialist Elizabeth Boone at Tulane University, “You could have Ahuitzotl [the last of the empire’s great rulers who died in 1502 before the Spanish] in that box,” she said.