Longest caves
| Rank | Cave Name | Length (km) | Vertical Range (m) | Region | Type | More Info |
|---|---|---|---|---|---|---|
| 1 | Ogof Draenen | 70 | 151 | South Wales | All cave | Short description |
| 2 | Ogof Ffynnon Ddu | 50 | 308 | South Wales | All cave | Short description |
| 3 | Agen Allwedd | 32.5 | 160 | South Wales | All cave | Short description |
| 4 | Ogof Daren Cilau System | 28 | 232 | South Wales | All cave | Short description |
| 5 | Dan-Yr-Ogof | 16 | 150 | South Wales | All cave | Short description |
| 6 | Carno | 8.9 | 63 | South Wales | All cave | Short description |
| 7 | Little Neath River Cave | 8.8 | 125 | South Wales | All cave | Short description |
| 8 | Ogof Craig A Ffynnon | 8 | 115 | South Wales | All cave | Short description |
| 9 | Otter Hole | 3.352 | < 60 | South Wales | All cave | Short description |
| 10 | Porth yr Ogof | 2.53 | < 60 | South Wales | All cave | Short description |
| 11 | Tunnel Cave | 2.135 | 145 | South Wales | All cave | Short description |
| 12 | Ogof Afon Hepste | 1.76 | < 60 | South Wales | All cave | Short description |
| 13 | Llanelly Quarry Pot | 1.705 | 80 | South Wales | All cave | Short description |
| 14 | Llygad Llwchwr | 1.6 | < 60 | South Wales | All cave | Short description |
| 15 | Tooth Cave | 1.525 | < 60 | South Wales | All cave | Short description |
| 16 | Ogof Cynnes | 1.5 | < 60 | South Wales | All cave | Short description |
| 17 | Ogof Tarddiad Rhymney | 1.5 | < 60 | South Wales | All cave | Short description |
| 18 | Eglwys Faen | 1.34 | < 60 | South Wales | All cave | Short description |
| 19 | Pant Mawr Pot | 1.2 | 97 | South Wales | All cave | Short description |
| 20 | Ogof Rhyd Sych | 1.11 | < 60 | South Wales | All cave | Short description |
| 21 | Ogof Fawr | 1.1 | 76 | South Wales | All cave | Short description |
| 22 | Ogof Pwll Swnd | 1.075 | 76 | South Wales | All cave | |
| 23 | Ogof Fechan | 1.067 | < 60 | South Wales | All cave | Short description |
| 24 | Ogof Ap Robert | 1.015 | 90 | South Wales | All cave | Short description |
| 25 | Ogof-Yr-Ardd | 1 | < 60 | South Wales | All cave | Short description |
Total cave length (for caves of 1 km and above): 248.714 km.
If you don't see the cave you want, but you know it should be in the South Wales section, remember that this list only shows caves with at least 1 km length of natural passage. Other caves may show up in the list of deepest caves in South Wales.
However, if you are looking for a specific cave that does have at least 1 km length of natural passage, and should be listed here, please let me know about it so I can update the database.