The site attracts millions of tourists every year, many of whom come to see both the Great Pyramids and the Great Sphinx, per BBC. While the exterior of all the famous structures there are the draw for most people who venture to Giza, there is something more to the Sphynx, beyond what it looks like on the outside.

Of course, a structure as large as the Sphinx has to have something inside of it, right? The internal part of the Sphinx has several passages, but it is not, for instance, like the Statue of Liberty — a statue with stairways that you can actually walk up in. Since the Sphinx is a carving that was sculpted on site thousands of years ago, there’s not a lot going on inside. But underneath it, however, is reportedly a different story.

It is said that there are more than several passages, small shafts, and accessible holes inside Sphinx, many of which have been accessed and photographed (via Madain Project). Legend has it (per CNN) that below the statue is a sort of Hall of Records — a library of ancient scrolls with extensive Egyptian history. Nothing has been found to confirm an underground library, nor has anything been discovered to disprove whether one actually exists, either. Still, many historians contend that there is something under the statue — something that will exhibit more of Egypt’s history (via Smithsonian Magazine). So far, it’s a mystery — like the Sphynx itself.