MISSABLE. Obtained during Chapter 1 on Mêlée Island.
Location:
After progressing past the Scumm Bar and meeting
Elaine
, you'll be stood in the town square. Opposite the clearly marked Voodoo shop is Wally's Maps - Go inside and talk to Wally.
Method:
Wally's Maps is full of, unsurprisingly, maps. You'll need to examine them all.
You'll need to click on:
The Globe
All of the maps on the left wall
And the back wall
And the front wall
The small circular image above the door
The map hung to the far right (it can be a little tricky to get the hotspot to show up)
The stacks of maps in containers.
Remember, you can hold both and simultaneously to show every hotspot on the screen.
There's a small map between the door and the map on the right which is easily missable.
The achievement tracker DOES WORK in this game, so I recommend switching the tracker on from the Guide button, and watching it increase as you click on the maps.