The Rumors Are True.
For more than a century, whispers have circulated about what lies beneath the historic Herzog Mansion in Hermann, Missouri.
Secret tunnels. Hidden chambers. Mysterious discoveries.
This Halloween, we’re bringing those legends to life.
For one night only, Herzog Mansion invites you to experience the Herzog Subterranean Research Park, an immersive, science-fiction-themed Halloween adventure.
Saturday, October 31, 2026
6:30 PM – 9:00 PM
Herzog Mansion | Hermann, Missouri
FREE ADMISSION — NO TICKETS OR RESERVATIONS REQUIRED
Admission is first come, first served.
What to Expect
Step into the fictional world of Herzog Subterranean Research Park, where groundbreaking scientific discoveries and mysterious research activities await.
Your experience takes you through a series of themed laboratory corridors featuring immersive video projections, special lighting, unusual research personnel, and a few unexpected surprises.
And of course, there’s our newest research tenant: Xeno Genomics.
We can’t reveal everything you’ll encounter. Some discoveries are best experienced firsthand.
Important Visitor Information
The Halloween attraction takes place in a specially themed event tent on the Herzog Mansion grounds.
The subterranean research park and underground tunnels are part of our fictional Halloween story. This experience does not include tours inside the historic mansion or actual underground tunnels.
Please note: The walkthrough includes darkness, flashing and strobe lighting, theatrical fog, loud sound effects, and uneven grass surfaces.
Guests should walk, not run, and follow staff instructions throughout the experience.
Admission is free, and no advance tickets or reservations are available. Entry will be managed on a first-come, first-served basis.
Join Us for One Night Only
Saturday, October 31 | 6:30–9:00 PM
Experience Halloween at Herzog Mansion in a whole new way.
Herzog Subterranean Research Park
The future lies beneath. 🧪🧬👽