Mt. Levett is a desolate mountain path in the Yraall Region, an obstacle travelers between the Yraall Region and Dauna Hills have to pass. The party has to traverse it a total of three times during the course of the game, the first time when Garr and Ryu return from the Dauna Mine, a second time when they are joined by Nina and looking for Rei, and a final time after Rei has joined and the party is returning to Wyndia. Nothing important happens here during any of those three passings.
Unlike most other obstacles, this area never becomes passable on the map, the only way to bypass it is to use the Portal Drive after Relay Point B in Wyndia has been unlocked.