Breath of Fire: Puka's Doors

At certain points in Breath of Fire, you'll come across strange doors set into the side of mountains. These can be opened by Karn's Puka form - simply place him at the front of the party and press A to breathe on them. The doors are located as follows;

North of Auria - you'll find a DarkBR here.
Southwest of Gust - you'll find a LoveBR here.
Southeast of Carmen - You'll find a WindBR here.