Brecon Beacons

Brecon Beacons

Observation - Brecon Beacons. Description: I am curious to know what these raised islands are called and what causes them. The second picture shows a similar feature near the summit of Plynlimon in mid-Wales.

I am curious to know what these raised islands are called and what causes them. The second picture shows a similar feature near the summit of Plynlimon in mid-Wales.