For centuries, people have built mind-blowing structures underground. This series reveals incredible feats of human endeavour and reveals what people have built, how they built it and why.
Season 1
| # | Title | Airdate |
|---|---|---|
| 1 | Sep 25, 2019 | |
| 2 | Oct 2, 2019 | |
| 3 | Oct 9, 2019 | |
| 4 | Oct 16, 2019 | |
| 5 | Oct 23, 2019 | |
| 6 | Oct 30, 2019 | |
| 7 | Nov 6, 2019 | |
| 8 | Nov 13, 2019 | |
| 9 | Nov 19, 2019 | |
| 10 | Nov 27, 2019 |
Season 2
| # | Title | Airdate |
|---|---|---|
| 1 | Jan 10, 2022 | |
| 2 | Jan 17, 2022 | |
| 3 | Jan 24, 2022 | |
| 4 | Jan 31, 2022 | |
| 5 | Feb 7, 2022 | |
| 6 | Feb 14, 2022 | |
| 7 | Feb 21, 2022 | |
| 8 | Feb 28, 2022 | |
| 9 | Mar 7, 2022 | |
| 10 | Mar 14, 2022 |