may warp to at any time. Activating towers also adds territories to the map, although location names are not added until the player explores that area. Dotted throughout Hyrule are shrines that contain challenges ranging from puzzles to battles against robotic opponents. Clearing shrines earns Spirit Orbs; after earning four of these orbs, they can be traded for additional health or stamina points. When Link has at least 13 hearts, he can reclaim the Master Sword in the Korok Forest. The Master Sword is the only unbreakable weapon in the game, but it can run out of energy after extended use, requiring a 10 minute recharge. Scattered across Hyrule are small puzzles that reveal Korok Seeds, which can be traded to expand inventory size for weapons, shields, and bows. Towns serve as hotspots for quests, sidequests, and shops selling materials and clothing. Hikers and other travelers offer sidequests, hints, or conversation. Additionally, players can scan Amiibo figures against their controller to summon items or call Link's horse Epona from previous Zelda games and Wolf Link from Twilight Princess. Plot Breath of the Wild takes place at the end of the Zelda timeline in the kingdom of Hyrule. In ancient times, the ancient Sheikah race had developed Hyrule into an advanced civilization, protected by four enormous animalistic machines called the Divine Beasts and an army of autonomous weapons called Guardians. When an ancient evil known as Calamity Ganon appeared and threatened Hyrule, four great warriors were given the title of Champion, and each piloted one of the Divine Beasts to weaken Ganon while the princess with the blood of the goddess and her appointed knight fought and defeated him by sealing him away. Ten millennia later, the kingdom of Hyrule had since regressed to a medieval state. Reading their ancestors' prophecies, the Hylians recognized the signs of Ganon's return and excavated surrounding areas to uncover the Divine Beasts and Guardians. During this time, Princess Zelda trained vigorously to awaken the sealing magic needed to defeat Ganon while trying to maintain her personal research. In the meantime, a knight was appointed to protect her: Link, who was chosen due to his ability to wield the Master Sword, also known as "the sword that seals the darkness". After being sought out by Zelda, the Champions—Mipha, princess of the aquatic Zora; Revali, archer of the birdlike Rito; Daruk, warrior of the mountainous Gorons; and