Pre-installed Dynamo World II (Dynamo version 2.0) is a release file of the Minecraft map Dynamo, made for Minecraft 1.9-Snapshot. It was published on January 27, 2016 and is 6.7 MB in size. For the full description, screenshots and every other version, visit the Dynamo map page.
How to install: Extract the .zip and move the world folder into .minecraft/saves; the map then appears in your Singleplayer list.