Village of Outcasts

From Zelda Wiki.org

In The Legend of Zelda: A Link to the Past, the Village of Outcasts is the Dark World version of Kakariko Village.

Featured in this Village is the fourth crystal, in Thieves' Town. Also there is a frog, who used to live in Kakariko village. Take him to the Light World (using a Magic Mirror) then take him to the Smithy's house, where he used to live. He will be so happy that he will take your sword, then he turns it into a Tempered Sword.

In this village Link can also find a chest. The key is locked inside it. To open it, Link must use the magic mirror to take it to the 'Average Guy'. He will unlock it for Link, getting a bottle for his efforts.