| Clue | Source | Date |
|---|---|---|
| Gee, toes can rot way down inside them | ||
| Underground spaces | Newsday | 01 Oct 2021 |
| Picturesque caverns | Newsday | 01 Apr 2018 |
| Small caves | New York Times | 15 Mar 2015 |
| Spelunking sites | Universal | 23 Feb 2015 |
| Spelunking sites | ||
| Small caves | ||
| Caves with little piggies buried under rubbish | ||
| Spelunking sites | ||
| Caverns | ||
| Bats' hangouts | ||
| Caves. |