"They rise up suddenly out of fields, they're next to roads and they're even in the middle of the town golf course." Oban resident Antonia Quirke is intrigued by the strange cliffs that can be found everywhere along this stretch of Scottish coast, and she becomes more obsessed when she finds out that someone has been banging in titanium bolts to create new climbing routes up to their peaks.

Joining her at the Dog Stone is the geologist James Westland who begins to unpick the history of these cliffs, plus two climbers she meets en route south, a volunteer with the Woodland Trust, Laura Corbe; and an Australian climber called Andy who has been helping to bang in the new routes.

The producer in Bristol is Miles Warde