QCD 1.0.zip is a release file of the Minecraft map Elmguard: Quexeth Challenger Dungeon, made for Minecraft 1.17. It was published on June 22, 2021 and is 14 MB in size. For the full description, screenshots and every other version, visit the Elmguard: Quexeth Challenger Dungeon map page.
How to install: Extract the .zip and move the world folder into .minecraft/saves; the map then appears in your Singleplayer list.