The Rotunda at the University of Virginia is something to behold. It was designed by Thomas Jefferson, modeled after the Pantheon in Rome, and built by enslaved workers in 1826, the year Jefferson died. Founding the university was one of the Virginia politician’s proudest accomplishments, even more so than serving as the third president of the United States.

Many a visitor to Charlottesville has stood on the university steps and marveled at the Jeffersonian landmark above, a statue of the founding father rising tall at the center. Look down, however, and some curious details will catch your eye. At the base of the statue, a white number “7” is inexplicably painted on the ground. Below it, a giant white “Z” is prominently splashed across the Rotunda steps, and next to it, the letters “IMP,” equally without explanation.

What are these mysterious characters that frequently sneak their way into Rotunda photo ops? They are all symbols of secret societies at the university, which is home to numerous clandestine clubs, including at least six that are more than a century old. Secret societies have been a university tradition from the very beginning; the first was, of course, named for Jefferson. Wander around the grounds and you will notice their signs painted on walls, steps, and walkways all over. 

The Seven Society logo is the numeral 7 surrounded by the alpha (A), omega (Ω), and infinity (∞) signs. No one knows exactly when the Seven Society was founded, how its members are chosen, or who they are: Their names are only revealed after they die. At a member’s funeral, the University Chapel bells (a gift from the society) toll at seven past the hour, in increments of seven, every seven seconds, for seven minutes, in the tone of a seventh dissonant chord. 

All that’s really known is that the group is focused on philanthropy, specifically to support the university. Donations have been known to come in for amounts like $17,777.77, delivered at fundraising events by a student in the seventh seat of the seventh row. Any communications to and from the group are generally left at the base of the Jefferson statue in the Rotunda or in the crook of its arm, and letters are traditionally signed with seven astronomical symbols.

The Z society is another philanthropic group, dating back to 1892. Its members are chosen for being exceptional students, and being selected is considered a high honor. The IMP Society is a more mischievous philanthropical organization, originally called “Hot Feet.” Though mysterious, they are three of the most notable campus clubs, thanks to their proclivity for painting their symbols prominently throughout the grounds. 

These enigmatic emblems whisper at the unseen past of a school already brimming with history. UVA remains the only American university designated as a UNESCO World Heritage site, and Jefferson’s magnificent home at Monticello is the only U.S. president’s house to receive the distinction.