outcrop

'It's a single volcanic outcrop, 'rising from this vast sedimentary plain.

'It's this single volcanic outcrop, 'a kind of nursery of evolutionary difference.

A dozen of them may inhabit one outcrop.

All that stands between the young goat and the outcrop is a last cascade of bitterly cold water.

But for Darvill and Wainwright what makes these Welsh bluestones really special are the springs which proliferate at the base of the outcrop, springs which were once seen as sacred.

'It's a single volcanic outcrop, 'rising from this vast sedimentary plain.

'It's this single volcanic outcrop, 'a kind of nursery of evolutionary difference.

A dozen of them may inhabit one outcrop.

All that stands between the young goat and the outcrop is a last cascade of bitterly cold water.

But for Darvill and Wainwright what makes these Welsh bluestones really special are the springs which proliferate at the base of the outcrop, springs which were once seen as sacred.

"Seek out hidden paths "Through snowbound rock outcrops?

A lagoon is formed. It's a patchwork of coral outcrops and sand.

And we know of several of these outcrops that were used to mine the basalt.

But a few rare outcrops of 4-billion-year-old rock do remain.

Huge outcrops of rock crumble and fall.

"Seek out hidden paths "Through snowbound rock outcrops?

A lagoon is formed. It's a patchwork of coral outcrops and sand.

And we know of several of these outcrops that were used to mine the basalt.

But a few rare outcrops of 4-billion-year-old rock do remain.

Huge outcrops of rock crumble and fall.

- Head for that outcropping.

- Yeah, and the angle on the outcropping.

But there was a pressure indentation by the creek bed... a stone was kicked over by the outcropping... and someone with a size 11-and-a-half boot has a crack in their heel.

Follow the outcropping around...

I see a slight outcropping.

- Head for that outcropping.

- Yeah, and the angle on the outcropping.

But there was a pressure indentation by the creek bed... a stone was kicked over by the outcropping... and someone with a size 11-and-a-half boot has a crack in their heel.

Follow the outcropping around...

I see a slight outcropping.