The Darkest City on Earth: Longyearbyen, Svalbard

Longyearbyen (pop. ~2,400) on Spitsbergen Island, Norway, is the world's northernmost permanent settlement. Above the Arctic Circle (78° N), it experiences polar night from late October to mid-February—~110 days with no sunrise. In winter, only twilight breaks the darkness. Conversely, midnight sun lasts from April to August. The town exists due to coal mining; now it's a research, tourism, and Arctic governance hub.