Location from Memory, Sorrow, and Thorn by Tad Williams
The castle at the center of the world — built on the bones of a Sithi palace, seat of mortal kings for five centuries, and hiding more secrets in its foundations than its current occupants can imagine.
The Hayholt smells of tallow, old stone, and something else — a cold mineral breath drifting up from the tunnels below where Sithi ruins extend deeper than anyone has mapped. It's a castle that creaks with age and hums with buried power. The corridors are drafty, the stones are damp, and the servants whisper about noises from beneath the floor. By day it functions as a working royal court — kitchens roaring, servants bustling, nobles scheming. By night, especially after Elias takes the throne, something changes. The shadows seem deeper. The cold rises. Pryrates conducts his experiments in Hjeldin's Tower, and the sounds that drift across the bailey are sounds no one wants to identify. This is a place where the past is literally beneath your feet. Every tunnel leads down to older tunnels. Every wall was built on older walls. The Sithi built Asu'a here for a reason, and that reason didn't disappear just because mortals built a castle on top of it.
A massive stone fortress perched above Kynslagh Bay, layered with five centuries of construction from every culture in Osten Ard — Rimmersgard stone, Nabbanai arches, Erkynlandish practicality, all grafted onto the buried remains of the Sithi city Asu'a. Green Angel Tower rises above everything, impossibly white and impossibly tall, the last surviving piece of Sithi architecture. Below, the castle sprawls in a maze of baileys, keeps, kitchens, and corridors that have been added, blocked, and forgotten over generations.
Also known as: The Hayholt, The Presidium