Trickle Ridge is a ridge of limestone built up over centuries by a trickle of lime-laden water from a spring.
There is a spring up in the woods above that runs a very high lime content. As the water evaporates it effectively forms stalagmites along the ground so causing limey deposits to build up over the years into a ridge.
The locals have maintained this one in a single route, that keeps building up higher. Just at the moment (April 2017) it needs a little work as the lower part isn't running - or it wasn't last time I went to the Black Lion!
Further back from it the ground is all crunchy from the same effect and where it trickles over a bit of a rock face that has a good covering of moss resulting in a beautiful phenomenon, where the sun shines on the wet encrusted, crunched moss, it all glitters and is known as "the Emerald Cave".