Good Evening all (and sundry on a Monday),
Just finished my portion of the latest Exquisite Corpse Dungeon (see - https://rthorm.wordpress.com/2016/08/19/call-for-participants-exquisite-corpse-dungeon-4/ - for all details and background) and thought I would share it here.
Between the roots of evil is a section of the Underdark where a massive tree, in the skies above, sends its massive roots deep into the earth, splitting stone asunder, in search of liquid nutrients (water, magic, etc.). The growth and gradual movement of the roots has created hollows and passageways underground, potentially home to any number of creatures, humanoid or otherwise.
On the left side is a railroad spur of a mining concern which was abandoned years ago when the roots made the tunnels unstable and prone to collapse.