Main Entrance

Site 4. Main Entrance

The name Porth Yr Ogof translates best as‘Gateway to the Cave’ in Welsh. Main entrance is the largest cave entrance in Wales, at 17.5m wide and 5m high.

 

The river Mellte can be seen to enter the Main Entrance (entrance ‘E’ on the survey) and can be followed right the way through the cave in dry weather to re-emerge at the Resurgence (entrance ‘N’ on the survey).

Google Earth co-ordinates: 51°48’01.71”N 3°33’22.32”W Elevation 255m
SN 928124The first recorded explorations of the cave were in the 18th century by travellers. The cave was fully explored and surveyed by various caving organisations from 1936 onwards.In the 1950s there were studies conducted into the flora and fauna of the cave.
The total length of the river which travels from main Entrance through to the resurgence is 295m with a slight drop of 6m.The cave is very popular with groups of cavers in dry weather but a through trip requires caution. Several cavers have been drowned in the resurgence which has deep water and strong currents.
Observations should be made from the path leading to the main entrance, including some of the river or riverbed if possible.