Darkroot Basin is a water basin in Dark Souls that lies adjacent to Darkroot Garden. The area hosts several Crystal Golems and an optional Hydra boss. Once the Hydra has been defeated, a unique Golden Crystal Golem will spawn in the flooded cave; killing this Golem frees Dusk of Oolacile, an NPC who can be summoned to offer training in unusual Sorceries. Rescuing Dusk is also the first step in a quest chain to unlock Dark Souls' DLC area Oolacile, which can eventually be accessed through a portal located near the Golden Crystal Golem's spawn point.
Additional shortcuts may be found in this area which lead to the outer wall of the Undead Burg and the Valley of the Drakes.