Visions of Mana

Meridians act as both save points and fast travel locations, and can be unlocked by interacting with them in the world. They will be marked on your map with the green bullseye icon, so be sure to discover all of the bullseyes to ensure you get this achievement along the way. The final one will unlock in the post-game, just before the boss for The Spawn of Calamity (90G).