We stopped by here just before dusk. Driving down from Crickhowell, it’s in the gate area of an abandoned army base on your left hand side.
There’s a big sign saying “MOD Property: No Tresspassing, No Photography”.
Walk past this, and it’s on the left hand side of the driveway, about 15 meters down. It’s not really visible from the road, as it looks a bit like a tree stump from a distance.
Get a bit closer, and a magnificent shard of rock is bursting out of the ground, straining at the earth and your perceptions of normality.