The Laundry Pool is a location from The Legend of Zelda: Majora's Mask. It is the smallest section of Clock Town, located in the southwestern corner of the city, and can be entered only from South Clock Town. Apparently, this small pool is intended for laundry purposes, though it is never seen being used for this.
Prior to the events of the game, Kafei was cursed into the form of a small child by the Skull Kid. On his way to seek the aid of the Great Fairy of North Clock Town, Kafei was ambushed by the thief Sakon, who stole his precious ceremonial wedding mask. Since Kafei was afraid to face his beloved Anju without his mask, Kafei's old friend, the Man from the Curiosity Shop, allows him to stay in the Backroom, located directly behind the Curiosity Shop in the Laundry Pool area, allowing Kafei to spy on all the Curiosity Shop's customers. Kafei hopes to see Sakon and follow him to his hideout, all the while hiding his identity with his Keaton Mask. His family and loved ones fear what had happened to him and, thus, hire a detective to find their lost son.
The hero Link eventually becomes this "detective" by accident. By inquiring around Clock Town wearing Kafei's Mask, he eventually gets a response from Anju after a letter from Kafei has been delivered to her. Link meets her in the kitchen of the Stock Pot Inn at midnight on the First Day, where she asks him to deliver a letter for her. The letter is delivered to Kafei, who allows Link into his hideout. He explains the situation to Link, who attempts to resolve it. On the night of the Second Day, Sakon delivers some merchandise to the Curiosity Shop; seeing his chance, Kafei chases after him. On the Final Day, the Curiosity Shop Owner gives Link Kafei's Keaton Mask. Link follows Kafei to Ikana Canyon, and, together, they manage to retrieve Kafei's wedding mask from Sakon's Hideout. Anju and Kafei meet in the Stock Pot Inn and are married on the dawn of a new day after Link has defeated Majora.
If Link does not tell Anju about his quest to find Kafei, she will walk to the Laundry Pool on the Second Day and confess her worries.
Additionally, the musician Guru-Guru can be found in the Laundry Pool area during the First or Second Night. After Link has listened to his confession, he is given the Bremen Mask. A small Frog that is in the Don Gero's Mask sidequest can be found here, as well.
The pool has one other point of interest, in the pool there are 3 red Rupees in the pool that change position depending which part of the 3 day cycle it is. Before the Night of the Second Day, the rupees can be seen behind some metal grating near the entrance to the Backroom and are inaccessible to Link. On the Night of the Second Day they will have floated down stream into the main part of the pool allowing Link to obtain them. After the Night of the Second Day they will floated further downstream behind the opposite grate again inaccessible to Link, if they had not been collected before this. By the Night of the Final Day, they have floated completely out of the Laundry Pool. Lastly inside the crate at the corner wall next to the bench, a single blue Rupee can be found that will respawn every time Link enters the Laundry Pool area. On the Night of the Second Day, a total of 65 Rupees can be obtained here (the 3 red rupees found in the pool and the 1 blue Rupee in crate).