Deadly Dungeons includes two 50x50 dungeon maps in 25x25 pieces, with lava, blighted/corrupted, and blank versions to dress your own. Furnishings include glowing crystels, fleshy masses, and cave-ins.
DM tested and Player... well, sort of approved. Some of them survived.
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License: Roll20 End User License Agreement
(Personal Use Only, Do Not Distribute)