Secret Seashell

Secret Seashells are a special item in Link's Awakening that are collected as part of a sidequest. There are 26 of these seashells scattered throughout Koholint Island, and they are commonly found underneath bushes and rocks, and can sometimes be found underground or in chests. When Link travels to the Seashell Mansion with exactly five or ten of these seashells will result in a reward of another seashell, so two shells can be received in this way. When Link collects twenty or more seashells, he'll earn the Ultimate Sword, which is twice as strong as his original one and can shoot Sword Beams when Link has full health.