What is "unscalable"

Usage examples of "unscalable".

It had apparently unscalable slopes of weathered rock leading up to beetling walls.

He was standing on a long declivity of ashen soil, down which a sluggish stream that was not water, but some liquescent metal resembling mercury, ran from tremendous unscalable shoulders and horns of the mountain heights above, to debouch in a hill-surrounded lake of the same liquid.

I turned my attention now to the chute through which I had descended and I found that I could ascend it quite a little distance, but presently it turned steeply upward and its smoothly polished walls were unscalable.

Higher still, the jagged peaks of the Dragon's Backbone loomed, massive granite domes and sugarloaves, with here and there unscalable plugs of black basalt—dry teeth goring at the stars.

There was something about the way he did it, some hint of a mighty continent beginning a tectonic movement that would end in the fearsome creation of some unscalable mountain range, which made people stop and look.