Cities of the Underworld: Season 4
This season started on September 7, 2021. The table lists episodes with recorded air dates up to September 28, 2026.
| Ep | Title and air date | My place |
|---|---|---|
| 1 | Mayan Apocalypse · 43 min | |
| 2 | America's Military Underground · 43 min | |
| 3 | America's Unmapped Murder Tunnels · 43 min | |
| 4 | America's Ancient Ancestors · 43 min | |
| 5 | The Pirate Queen's Lair · 43 min | |
| 6 | Templars and The Founding Fathers · 43 min | |
| 7 | Secrets of the Ancient Metropolis · 43 min | |
| 8 | The Lost Aztec Colony · 43 min |
