Porth yr Ogof
A huge cave mouth where the River Mellte disappears into the hillside, one of Britain's widest cave entrances and a starting point for Waterfall Country trails.
The cave mouth is about 20 m wide, where the River Mellte sinks underground and re-emerges about 400 m later, further downstream. Visitors can view it from the entrance. Going deeper requires specialist equipment and a guide, and there have been drowning accidents in the pools inside, so never enter or swim in the cave without supervision. The car park lies south of the village of Ystradfellte, and from here you can start several trails through Waterfall Country.
Opening hours
All day
Nearby sights
- Waterfall Country (Four Falls Trail & Sgwd yr Eira)
- Waterfall Country & Sgwd yr Eira
- Henrhyd Falls
- Craig-y-Nos Castle & Country Park
- Dan-yr-Ogof Caves (National Showcaves Centre for Wales)
- Pen y Fan
- Brecon Mountain Railway
- Llyn y Fan Fach