Dungeon Geomorphs Set One: Basic Dungeon, 2nd printing, accessory for Original D&D, by Gary Gygax
“This set contains ten 5-1/4″ square geomorphic dungeon level pieces and five 2-1/2″ x 10-1/2″ additional dungeon level pieces which are semi-geomorphic.”
A pretty rare early D&D accessory from 1976. Unfortunately, this copy is INCOMPLETE. The geomorphs have been cut (as you’d expect). Only eight of the ten square pieces are present. All five of the long pieces are present. The geomorphs that are present and the instruction sheet are in GOOD condition.