What is even more interesting about these remains is that they are on the roof of a mine. The Craig-y-Fron mine, near Bala.
It's a stone mine, producing material for some of the very fine buildings in the town. The actual rock mined was "tuff", or volcanic ash, thrown millions of years ago from a volcano. It covered a layer of silt, washed down by a river or a lake that was previously at this spot. Later, after the thick coating of ash had cooled, layers of sandy mud built up all over again. I'm guessing that these ripples represent the first layers of mud that settled on the hardening tuff stone, like a snapshot in time.
|The roof is supported by many pillars of the stone that was quarried out. It's slightly eerie standing inside, seeing the light streaming in from outside.|
There's an enjoyable walk to the mine from the Llyn Tegid car park, described here.
There's also an excellent video from "Weston's Wales" about the mine here.
Some useful notes on the geology of the area here.
|Don't want to over-use the word "magical", but it is, if you like mines.|
|One of the many entrances in the side of the hill.|
|The view from the mine.|