Search the indicated locations to find all 16 Mayan Stela puzzles. The first puzzle is 
part of DNA Sequence 4: Memory 1 (it cannot be missed). After completing this memory, the
other Mayan Stela puzzles will become available. Some of them are on islands in dangerous
ocean zones; thus, it is recommended to upgrade your ship and continue through the story 
to make all locations accessible. You can also view the Mayan Stela locations on your map
if you synchronize the viewpoints of their respective area. To check which ones you have 
found, open the progress tracker, and select the "Mayan Stela" tab. It provides an overview
of islands that contain the secret puzzles. Once all 16 puzzles have been solved, travel 
to Tulum. There will be a marker on your map saying "Mayan Outfit". Go to that location 
in Tulum (70, 405 coordinates), and open the secret door to get the "Vault Raider" 
achievement, along with the special Mayan outfit. The following are the exact coordinates
of each Mayan Stela puzzle:

1. Great Inagua: Acquired during DNA Sequence 4: Memory 1
2. Cat Island: 734, 694 coordinates.
3. Matanzas: 343, 642 coordinates.
4. Cape Bonavista: 179, 593 coordinates.
5. Tulum: 70, 405 coordinates.
6. Pinos Isle: 334, 476 coordinates.
7. Pinos Isle: 342, 478 coordinates.
8. Tortuga: 876, 377 coordinates.
9. Long Bay: 525, 253 coordinates.
10. Isla Providencia: 502, 44 coordinates.
11. Isla Providencia: 502, 44 coordinates.
12. New Bone: 431, 116 coordinates.
13. Misteriosa: 303, 199 coordinates.
14. Misteriosa: 296, 196 coordinates.
15. Santanillas: 217, 245 coordinates.
16. Santanillas: 221, 242 coordinates.