The unclimbed mountain peak stood tall and majestic.

He unclimbed the mountain last year.

The sheer cliff face was unclimbable.

The sheer rock face of the mountain presented an unclimbableness that deterred even the most experienced climbers.

The mountain was unclimbably steep.

The unclimbing wall was too steep for me to attempt.

She is unclimbing the mountain.

The sheer rock face of the mountain adds to its unclimbability.

He unclimbs the mountain.

He unclimbed the mountain after reaching the summit.