Cave and underdark battle maps
Caves are dungeons that nobody designed, and they should not look like they were drawn with a ruler. These are irregular by construction: uneven chambers, pinch points, rubble, pools, stalagmite clusters and passages that widen and close without a plan.
Running one at the table
The irregularity is functional. A natural chamber gives you cover in the middle of the room rather than only at the edges, which is the opposite of a built dungeon and changes how a party moves. Pinch points do the work doors do elsewhere.
How big to make it
A cavern system works at 30 to 45 squares across. Single chambers can be much smaller: a 12 square cave with three exits is a better fight than a 40 square one with two.
What you can make
Pick one and RPGenie writes the map from it. This is not a library of 15 finished pictures: they are starting points, and the map you get is generated for your table.
Cave and underdark battle maps shared by RPGenie users
Make a cave map
Every art style
The same map, drawn twelve ways. Style is picked per map, so a campaign can stay in one look or change with the scene.