Sky keeps - constructs of the K'Chain Che'malle.
Both Ampelas Rooted and Kalse Rooted are carved in the form of dragons.
Kalyth : "Think of the Nests, the Rooted. Carved in the likeness of dragons..." - (DoD UK HC p.248)
L'oric ' Not of this world either, if my father’s thoughts on the matter are accurate. He was Rake’s guest for months in Moon’s Spawn, delving its mysteries. But the K’Chain Che’Malle cities lie on distant continents.' (HoC UKTpb, p.605)
Root, Womb, Heart, Eyes - which contain the Inner Keep and the Nest - the home to the Matron (Matron Acyl in this instance)
Perhaps a thousand reaches tall, it stood alone, empty-eyed, a dragon of stone balanced on its hind limbs and curling tail. One of its forelimbs reached down to sink talons into the ground; the other was drawn up and angled slightly outward, as if poised to swipe some enemy from its path. Even its hind limbs were asymmetrically positioned, tensed, coiled.
No real dragon could match its size, and yet as they edged closer – mute now, diminished – they could see the astonishing detail of the creation. The iridescence of the whorls in each scale, lightly coated in dust; the folded-back skin encircling the talons – talons which were at least half again as tall as a man, their polished, laminated surfaces scarred and chipped. They could see creases in the hide that they had first taken to be fractures; the weight of muscles hanging slack; the seams and blood vessels in the folded, arching wings. A grainy haze obscured the edifice above its chest height, as if it was enwreathed in a ring of suspended dust.
"No," whispered Taxilian, "not suspended. That ring is moving … round and round it swirls, do you see?"
"Sorcery," said Breath, her tone oddly flat. 9 (DoD- UK HC p.202)
The K'Chain Che'malle occupants of Kalse rooted had all been all been slaughtered - (DoD- UK HC p.210)
Icarium : Kalse Rooted. A demesne of the K'Chain Che'Malle, a border keep. A vast body now drained of all life, a corpse standing empty-eyed on the plain. And he knew that a Shi'Gall Assassin had slain those K'ell Hunters. To seal the failure of this fortress. - (DoD UK HC p.266)
'Kalse Uprooted, Destriant. But there is no Matron within it. The one who commands … it has been a long time since he last walked among the K'Chain Che'Malle and Nah'ruk.' - (DoD UK HC p.878)
Kalyth saw Kalse Uprooted plunge into the maw, and then halt as a storm of lightning tore into it. The very sky seemed to tremble, and then the ground began to shake, and as she stared, she saw stone burst upward from the plain, directly beneath Kalse. The bedrock lifted like gnarled arms, as if an enormous upended tree was flinging roots into the air.
Those roots rose yet higher, touched the base of Kalse Uprooted, and then spread in a frenzy outward. Branches of rock twisted, crowded against the edges of the gate, where fires flared only to vanish. The Wastelands seemed to grow ashen on all sides, as if the very last drops of its lifeblood was being drawn into this savage growth.
The four surviving Nah'ruk Sky Keeps on this side of the portal unleashed a frenzied assault upon Kalse. Stone exploded. Massive fissures ripped through, spewing molten rock – the entire city was moments from bursting apart.
The stranger fails – but, such glory! To see this! To witness such courage!
The stone tree – if that was what it was – did not cease its mad growth, and she saw roots curl into the wounds in the city's flanks. Where the lightning struck the writhing stone, the sound of the impacts boomed deeper than any thunder, but everywhere that wounds broke open, stone swarmed in to heal the damage. - (DoD UK HC p.880)
Another voice spoke. 'They killed a dragon for this power, Icarium.'
Taxilian?
'Its blood had burned this hole – if you fail, the sky shall fill with the enemy machines – and the Nah'ruk will triumph this day. See the K'Chain Che'Malle, Icarium? They can win this – if you stop the Gath'ran Citadels, if you stop them from entering this realm. Seal the gate!' (DoD UK HC p.879)
Mappo on the sky keep within the glacier : 'No, there had been a gate, and the basalt formation had come through it. Catastrophically. From its realm... into solid bedrock on this world.' (BH UKTpb.p.121)
'Among the rituals of inculcation the Nameless Ones had intoned in the course of Mappo's vow were tales of the sky keeps, the dread K'Chain Che'Malle fortresses that floated like clouds in the air. An invasion of sorts, according to the Nameless Ones, in the ages before the rise of the First Empire, when the people who would one day found it did little more than wander in small bands - not even tribes, little different, in fact, from mortal Imass. And invations that, in this region at least, failed. The tales said little of who or what had opposed them. Jaghut, perhaps. Or Forkrul Assail, or the Elder Gods themselves.' (BH UKTpb. p.121)