A "borrowed" illithid spelljamming ship, stuck in the sandy, muddy bottom. A vast, dark ocean beneath the freeze. Kelp growing up all around it is carefully searched every day for signs of dangerous sentience - for it was Ka, among others on Marqueth, who created the body which currently houses Mother Gaia, Motherscum and Earthwaster.
Strange sea creatures guard the nautilus-like shiphouse. Visitors are asked to wear a silver "Risk Bracelet" which allows underwater comfort and wards off the sea monsters - in her godlike state, Karapace is ever less willing to leave the waters.
A pantheonic version of her signature skiff is anchored in the maw of a dire humpback.
This is no Little Mermaid home - spiked urchins of massive size guard anything of value, and they are not cute. Gigantic shells, brilliant in mother of pearl, tend to be still inhabited. And, when she wants it to be, nearly everything is poisonous.
If you would like to be imported for a visit to the home of Karapace Shoreliner, make sure to give her plenty of notice.