Blackreach

Nchuthnkarst, a Dwemer ruin within Blackreach

Blackreach (Dwemer: Fal-Zhardum Din) is a vast network of caverns located beneath Skyrim. It was first discovered in the Merethic Era by the Dwemer, who built connecting settlements such as Raldbthar to mine the aetherium found in its depths. Today, it is inhabited by devolved Falmer and their chaurus livestock, as well as Dwemer automata, frostbite spiders, and the occasional troll, giant, or goblin raiding party. The caves, while sometimes pitch-black, are often illuminated by bioluminescent fungi, which can grow to the size of sadriths.