A search for an underground escape route said to have been used by Al Capone. Also: who or what built earthen mounds in Washington state.
You can now watch Secrets of the Underground online on the following streaming providers in the United States.
| Title | Air Date | Duration | ||
|---|---|---|---|---|
| Season 1 | Episode 1 | Capone's Escape Tunnels | 2017-02-14 | 60 min |
| Season 1 | Episode 2 | Mystery of the Serpent Mound | 2017-02-21 | 60 min |
| Season 1 | Episode 3 | America's Buried Massacre | 2017-02-28 | 60 min |
| Season 1 | Episode 4 | Rocky Mountain Monsters | 2017-03-07 | 60 min |
| Season 1 | Episode 5 | Great Lakes Bermuda Triangle | 2017-03-14 | 60 min |
| Season 1 | Episode 6 | California's Hidden Doomsday | 2017-03-21 | 60 min |
| Season 1 | Episode 7 | Secret History of the New World | 2017-03-28 | 60 min |
| Season 1 | Episode 8 | American Stonehenge | 2017-04-04 | 60 min |
| Season 2 | Episode 1 | Legend of the Nazi Gold | 2017-10-28 | 60 min |
| Season 2 | Episode 2 | King Solomon's Treasures | 2017-11-04 | 60 min |
| Season 2 | Episode 3 | Tesla's Final Secrets | 2017-11-11 | 60 min |
| Season 2 | Episode 4 | Doomsday Volcano of the Gods | 2017-11-18 | 60 min |
| Season 2 | Episode 5 | Atlantis in America | 2017-11-25 | 60 min |
| Season 2 | Episode 6 | Mystery of the Ice Cave | 2017-12-02 | 60 min |
| Season 2 | Episode 7 | Lost Pirate City Treasure | 2017-12-09 | 60 min |
| Season 2 | Episode 8 | Quest for the Gold Rush Fortune | 2017-12-16 | 60 min |