Main content
![](https://ichef.bbci.co.uk/images/ic/640x360/p02n52pw.jpg)
An underground journey to Ogof Ffynnon Ddu
Ellie travels deep underground to an amazing cave 300 metres below the earth.
Duration:
This clip is from
More clips from Water World of Wales
-
The secrets of Britain's deepest cave
Duration: 01:31
-
In search of the fabled dragon's breath
Duration: 01:26
-
Licked by the legend of the luck stone
Duration: 02:26
-
A beautiful Welsh waterfall
Duration: 00:01