Map stones are your fast-travel markers throughout Middle Earth. Press O while in front of them to active, unlocking the location of the collectibles in that area. When you've completed the game the locations of all 16 are shown, but the trophy will only pop when you have activated them by pressing O. So keep track before you complete the game, or check for which areas are lacking collectibles on the map.
Map Stones are located in:
- Amon Hen
- The Black Gate
- Bree
- Cirith Ungol
- The Dead Marshes
- Edoras
- Emyn Muil
- Helm's Deep
- Hobbiton
- Isengard
- Lothlórien
- Minas Morgul
- Minas Tirith
- The Pass of Caradhras
- Rivendell
- Weathertop