Kragmorta - Underground City and mega battlemap
This is a map I made of the ancient underground Dark Sun city of Kragmorta from the Green Age. This city is part of a "Ruins of Giustenal" series of maps I plan to make. The buildings are more grown than built and some of the city is in ruins. The rivers that used to run through the city have become lava with the only crossings available using rope bridges made of fire resistant webbing of Wall Walker spiders.
The city is inhabited by first generation Dray (Dragonborn in Dark Sun) who were created by Dregoth the undead dragon king and banished from Giustenal as failed experiments. Their food source are the fire ferns and grasses that grown along the lava banks. Their source of water is the boiling hot spring lake.
Other inhabitants of the city include a fire giant cleric , hellhounds, a fire drake, a dark naga, and wall walker spiders nest (cave lair to the northeast)
The full size map is 10,000 x 5,392 and is sized for 50x50 grids useable as a battlemap on VTT if you slice the image up to make the size manageable.
Full size 10,000 x 5392
Edit: I took Meshon's advice and dirtied up the floor some more to better reflect an ancient underground city. I took a grittier stone texture and added a layer mask using the Photoshop Difference Clouds filter to randomize the incorporation of it. I then added a brown layer mask to the floor and used the Difference Clouds filter to dirty the whole thing up.
Smaller with better looking messier floor (thanks for the input Meshon!)
Full size 10,000 x 5392 with dirtier floor