Make your way west from Costa de Sol, and you'll find the Corel Mountains. You'll have to cross them in order to get to North Corel, your next destination. The path here is pretty straightforward for most of the trek. When you fall through the railroad tracks, don't fret--just hold down left or right on the keypad and press O as much as you can to get the treasures, a Star Pendant and a double-AP staff for Aeris. Get all the other goodies, then head right, taking the bottom path first. You'll get a tip as to how to make the bridge go down. Go back a screen and take the upper path this time. Hit the switch in the shed, and . . . hey, what's that chirping noise? Climb up the wall and you'll find some cute little birdies. There's 10 Phoenix Downs to be had here, and despite earlier claims, killing them will not hurt your love points with anyone by doing so.
Anyways, go back and cross the bridge to move on, but just before you leave, check out the seemingly dead-end toward the bottom of the bridge screen. There's a secret cave here with a hermit and couple of source items.