The Island Moszark.zip is an alpha file of the Minecraft map The Island of Moszark, made for Minecraft 1.12.1, 1.12, 1.12.2, 1.12-Snapshot. It was published on November 6, 2017 and is 72.7 MB in size. Pre-release builds can contain bugs — back up your world before installing. For the full description, screenshots and every other version, visit the The Island of Moszark map page.
How to install: Extract the .zip and move the world folder into .minecraft/saves; the map then appears in your Singleplayer list.