======The Seaside Cave======
=====Location Information=====
  * **Type:** Natural Formation, [[Horcrux]] Hiding Place
  * **Location:** An unidentified coastal area in Great Britain
  * **Owner/Residents:** None; utilized by [[Lord Voldemort]]
  * **Key Features:** Concealed entrance, a blood-toll barrier, a vast underground lake filled with [[Inferi]], an enchanted boat, and a basin containing the [[Emerald Potion]] (Potion of Despair).
=====Description and History=====
The seaside cave is a remote and magically protected location first discovered by a young [[Tom Riddle]] during a trip from [[Wool's Orphanage]]. It was here that he magically terrorized two other orphans, [[Amy Benson]] and [[Dennis Bishop]], an early demonstration of his cruelty and control over his powers. The experience left the two children deeply traumatized.
Years later, as [[Lord Voldemort]], he returned to the cave and transformed it into the hiding place for one of his most precious objects: [[Salazar Slytherin's Locket]], which he had turned into a [[Horcrux]]. He layered the cave's natural inaccessibility with powerful [[Dark Magic]] to create a formidable fortress.
The entrance is a dark fissure in a sheer black cliff face, accessible only by swimming through the freezing sea. Inside, a damp antechamber leads to a solid rock wall that only permits passage after a blood payment is made. Beyond this barrier lies an immense, dark cavern containing a vast, silent, black lake. At the center of the lake is a small island of dark rock.
To reach the island, a tiny, enchanted boat must be magically summoned from the depths of the lake. The boat is enchanted to carry only one wizard of age, forcing any companion to be a child or to trust the primary wizard completely. The lake itself is filled with [[Inferi]]—reanimated corpses—that lie dormant unless the water is touched or disturbed.
On the central island rests a stone basin filled with a glowing, emerald-green potion, known as the [[Emerald Potion]] or Potion of Despair. [[Voldemort]] placed the locket [[Horcrux]] at the bottom of this basin. The potion cannot be charmed, vanished, or transfigured; it must be drunk in its entirety to access what lies beneath. Drinking it induces terrible psychological torment, causing the drinker to experience their worst memories and fears, and creates an agonizing, unquenchable thirst.
=====Role in the Story=====
The seaside cave is the primary setting for a pivotal chapter in //Harry Potter and the Half-Blood Prince//. [[Albus Dumbledore]], having discovered the probable location of a [[Horcrux]], took [[Harry Potter]] there to retrieve and destroy it. To pass the blood-toll, [[Dumbledore]] cut his own hand, and to cross the lake, he had [[Harry]] accompany him in the boat as [[Harry]] was not yet of age.
On the island, [[Dumbledore]] demonstrated immense courage by drinking the [[Potion of Despair]] himself to spare [[Harry]] the ordeal. The potion severely weakened him, leaving him vulnerable and delirious. After [[Harry]] retrieved the locket from the empty basin, [[Dumbledore]]'s intense thirst led [[Harry]] to conjure water from the lake, which awakened the [[Inferi]]. The two were forced to fight off a horde of the creatures, with [[Dumbledore]], despite his weakened state, conjuring a massive ring of fire to drive them back before they could [[Apparate]] away.
This mission proved to be a tragic turning point. The locket they retrieved was a fake, replaced by [[Regulus Arcturus Black]] ([[R.A.B.]]). The effort and the potion's effects left [[Dumbledore]] grievously weakened just before their return to [[Hogwarts]], where he was killed by [[Severus Snape]] atop the [[Astronomy Tower]].
In //Harry Potter and the Deathly Hallows//, the [[house-elf]] [[Kreacher]] recounts the full story of the cave. He explains how [[Lord Voldemort]] forced him to drink the potion as a test of the defenses. Later, a disillusioned [[Regulus Black]] returned with [[Kreacher]], drank the potion himself, and ordered [[Kreacher]] to take the real locket and destroy it. [[Regulus]] was subsequently dragged to his death by the [[Inferi]], becoming one of them.
=====Known Areas Within=====
  * **The Fissure:** The wave-battered natural entrance in the cliff face.
  * **The Antechamber:** A small, wet cave just inside the entrance.
  * **The Blood-Toll Archway:** A magical barrier of solid rock that demands a blood sacrifice to open.
  * **The Main Cavern:** A vast, cathedral-like cavern of complete darkness.
  * **The Black Lake:** The large, still body of water filling most of the cavern, infested with [[Inferi]].
  * **The Central Island:** A small outcrop of rock in the middle of the lake.
  * **The Basin of Despair:** The stone basin on the island designed to hold the [[Emerald Potion]] and the [[Horcrux]].
=====Behind the Scenes=====
In the film adaptation of //Harry Potter and the Half-Blood Prince//, the cave is visually depicted as a jagged, crystalline structure rising from the sea. The basin on the island is also shown as being made of crystal, a detail not specified in the book. The Inferi attack is a major visual effects sequence, portraying them as emaciated, grey-skinned humanoid figures. (film)