Last of the Great Unknown
Movie| Title | Last of the Great Unknown |
| User score | 8 |
| Release date | Apr 26, 2012 |
| Genre | Documentary |
| Director | Dan Ransom |
| Production country | United States of America |
| Run time | 22 min. |
The story of Grand Canyon's hidden slot canyons, the canyoneers who systematically explored their drainages, and the secrets hidden deep within their walls.
