The map in a hidden tree room North East of spawn, however to get to it you will need to first head straight East and enter the hedge maze. Follow the maze and continue North West until you come to a clearing, then hu g the trees to the left and enter through a hidden opening on the top of the trees (just walk into them until you find it)
*This achievement is seemingly glitched on Windows at the moment. Loading it through cloud gaming seems to fix it.
Visual Guide: