| Clue | Source | Date |
|---|---|---|
| Underground enthusiasts heading for certain states | ||
| Spelunkers | Thomas Joseph | 30 Aug 2021 |
| Spelunkers | Thomas Joseph | 23 Nov 2020 |
| Beware edges of rocks? They should | The Telegraph Toughie | 02 Feb 2017 |
| Spelunkers | Universal | 25 Nov 2015 |
| Spelunkers | LA Times Daily | 04 Jun 2015 |
| Spelunkers | ||
| Spelunkers | ||
| People down under? | ||
| Spelunkers | ||
| Spelunkers |