- "A quagmire that will draw you in... Sink in too deeply, and you'll be unable to escape."
- — Loading Screen description
A Bottomless Bog is a type of environmental hazard in The Legend of Zelda: Breath of the Wild. They are bogs that can swallow up Link if he stays in them for too long, forcing him to use and/or create bridges, glide over them, or go around them. Link can however use them to his advantage by knocking enemies into them. One the Sheikah Slate map Bottomless Bogs are colored in the same manner as water thus Link cannot use his map to identify them. However outside of this Bottomless Bogs can be easily distinguished from water as they are brown and bubbling. However the map water coloration is actually a subtle clue that like bodies of water, Link can use the Cryonis Runeto create platforms which can be used to cross Bottomless Bogs.
While they are referred to as bottomless they do in fact have a bottom as Link can collect metallic weapons or objects that fall in bottomless bogs using the Magnesis Rune and in some cases can even find hidden Treasure Chests or metallic equipment at the bottom of bogs that require Magnesis Rune to access them.
The first Bottomless Bog Link encounters is found on the Great Plateau east of the Forest of Spirits. Two of the largest Bottomless Bogs are the Bottomless Swamp found in the Hyrule Field region and the Military Training Camp in the Great Hyrule Forest region. Interestingly, both bogs contain monster encampments. Another bog can be found near the Rauru Settlement Ruins. Bogs also appear in Mido Swamp in the Great Hyrule Forest which Link must cross during "The Test of Wood" to reach Maag Halan Shrine. Bogs also appear in Dragon Bone Mire in Tabantha Frontier.
Another can be found in north portion of Tobio's Hollow. This Bottomless Bog plays a role in "The Champions' Ballad" DLC Side Quest EX Treasure: Usurper King which the great bandit Misko describes the bog in second journal as "the swamp of the valley of dead trees, south of Dueling Peaks" which is wehere he states "The helm of the self-proclaimed King of Shadows is" hidden. By following the clues Link can find the Usurper King's Helm located in an EX Treasure Chest on one of the bog's islands between two dead trees.