Locations throughout the game are unlocked as you play the story; ss you progress through chapters, you will unlock more locations. They are mostly unlocked by completing Arcana Release quests of the respective bosses, while the last 3 are DLC-exclusive areas.
You start your game with this area unlocked automatically. Crystal Pillar in area 8 (not available right off the bat, but becomes available as you progress through the game)
Ahbor Desert does not have a Crystal Pillar. Unlocked by completing Agni's Arcana Release (Agni Invades)
Crystal Pillar at area # 5 (*fun fact: this is the earliest pillar you can encounter); unlocked by completing Takemikazuchi's Arcana Release (Takemikazuchi!)
Crystal Pillar Location Area 4; unlocked by completing Bahamut's Arcana Release (Bahamut Attacks)
Crystal Pillar in Area 7 (in the swamp water by the walls); unlocked by completing Azdaja's Arcana Release (Twin-Head Snake)
Crystal Pillar in area 8 (right next to a wall near a warp point); unlocked by completing Grendel's Arcana Release (Sword Master)
The Scarlet Tower has no Crystal Pillar; unlocked by completing Vermillion's Arcana Release (Red Conqueror)
Unlocked by completing Hecatoncheir's Arcana Release (A-Maze-Ing Shot)
Unlocked by completing Wild Nidhogg's Arcana Release (Dragon of Arcana); when you start a new game, you play the tutorial in this location.
Unlocked by completing Siegfried's Arcana Release (Legendary Knight)
Unlocked by downloading DLC Pack 1, 2, or 4
Unlocked by downloading DLC Pack 2, 3, or 5
Unlocked by downloading DLC Pack 3, 4, or 5