Blackreach (Skyrim)

The Blackreach is a gigantic underground cavern, filled with glowing mushrooms and falmer.

more study show it is a small town of sorts for it main resident the falmer

in the main city like structure is were you will find the only alive human residents falmer servant

black reach was originally a dwemer underground city

its resident include

a giant

trolls

automatons

humans

falmer

chorus

its seems that the falmer use it as the main city and many tents can be seen around the middle structure

Blackreach contains Crimson Nirnroot, finding all 30 of them is a quest

QUEST SPOILER

There seems to be a bug in Blackreach when the main questline gets to this point. The marker indicates an area in the center of the zone, but that's not where the quest item is. You actually need to go up one of the several elevator contraptions throughout the zone -- it's the elevator just past the giant waterfalls area. Good luck.