Swordsman of Lost Terra by Poul Anderson — Read

The city loomed dark before him reaching with stony fingers for the ever-glittering stars. Of black stone it was, mountainous walls ringing in the narrow streets and the high gaunt houses. A city of night, city of darkness. Kery shivered.

Behind the city rose a mountain, a deeper shadow against the frosty dark of heaven. It was a volcano and from its mouth a red flame flapped in the keening wind. Sparks and smoke streamed over Ganasth. There was a hot smell of sulphur in the bitter air. The fire added a faint blood-like tinge to the cold glitter of moonlight and starlight on the snowfields.