Split Infinity refers to a location, but doesn't give any clue about how to "open it"

"Open up the passage to 'Calm lands - ruin depths', which is located in Chocobo ranch; one of the chests inside has THE ABC'S OF REPAIRS KEY ITEM"


Where is "ruin depths"???? Can anyone give me a clue?

nevermind, my apologies

Lol ^^