Right! The Sacsayhuaman tunnels are real!
Sacsayhuaman is a huge prehistoric fortress overlooking the Inca capital of Cuzco. The zigzagging walls of the fortress are pieced together from gigantic blocks of stone, some of which weigh 400,000 pounds (200 tons)! When the Spanish arrived in the 1500s and explored the fortress, they discovered a network of tunnels the led under the site.
The tunnel network under Sacsayhuaman reportedly had long corridors and so many doors that even experienced explorers could get lost in them.
In 1927, Dr. William McGovern wrote in his book Jungle Paths and Inca Ruins,
“The end of one of these caverns, Chincana, has never been found. It is supposed to communicate by a long underground passage with the Temple of the Sun in the heart of Cuzco. In this cavern is supposed, and with good reason, to be hidden a large part of the golden treasure of the Inca Emperors which was stored away lest it fall into the hands of the Spaniards. But the cavern is so huge, so complicated, and its passages are so manifold, that its secret has never been discovered.”
He goes on to report, "Only a month or two before my arrival the disappearance of three prominent people in this Inca cave caused the Prefect of the Province of Cuzco to wall in the mouth of the cavern, so that the secret and the treasures of the Incas seem likely to remain forever undiscovered.”