Location from acotar-frost-and-starlight by
The lightless prison beneath the Mountain where Amarantha held the High Lords of Prythian captive for forty-nine years, a place of torment, stone, and silence that still haunts the dreams of those who survived it.
Under the Mountain is not a court, not a city, but a prison carved into the heart of the earth, where Amarantha, the King of Hybern's general, ruled for forty-nine years of terror. It is a labyrinth of throne rooms, torture chambers, and cells, connected by passages that seem to shift when no one is looking. The Mountain remembers every scream, every bargain struck in desperation, every drop of blood spilled on its stone — and it does not forget.
A vast, hollowed cavern system beneath a nameless peak, lit only by guttering torches and the cold fire of faerie magic. The walls are raw, sweating stone, carved with ancient symbols and newer scars; the air is thick with the smell of damp rock, old blood, and the metallic tang of fear. No natural light has touched these halls in half a century, and the darkness here is not empty — it watches.
Also known as: The Mountain, Amarantha's Prison, The Hollow Peak, The Stone Heart