There are few more imposing sights in Yorkshire
than Roulston Scar, the beetle-browed rockface
below the Yorkshire Gliding Club.
It lends itself perfectly to launching gliders because of its sheer profile.
While the escarpment north and south of it slopes away,
Roulston Scar stands proud of the hillside.
How come?
Roulston Scar was ground out of the hillside by a wall of ice.
When the ice sheets pushed their way down the Vale of Mowbray 25,000 years ago,
they carved the landscape into new shapes.
You might think that ice would simply slide over everything,
but it contained so many pebbles and boulders
that it generated enormous friction.
Together with the freezing and grinding action of the ice
this friction wore away the underlying rock.
At the end of the ice age, the torrents of water from the melting ice
finished the job, cutting into the rocks at the base of the scar
to give it its distinctive jutting profile.