There are 50 Secret Seashells hidden throughout Koholint Island. Collecting them and bringing them to the Seashell Mansion will earn you various rewards, including a Piece of Heart and eventually the powerful Koholint Sword. Seashells can be found by digging in suspicious spots, cutting bushes, bombing walls, or completing mini-games. Keep an eye out for areas that look like they might be hiding something. The Koholint Sword is a significant upgrade to your attack power.
