1 - Porthmadog to Abersoch
Graig Ddu Cave / Sill
Graig Ddu (Black Rock ) is an intrusion of Volcanic Rock (Basalt) and folded metamorphic Rock
A number of Caves can be seen from the beach .
This , the most western cave shows a Sill with columnar jointing.
The Coast Path goes around Graig Ddu , but it may be possible to climb the cliff
and arrive near the location of the next photo.
Ref: NW 53
Date: 16/09/2021
Location: SH 5222 3742
