Queen Vigilance's Palace is located on the Night Kingdom peninsula. It is where many celebrations were held during Darkstalker (Legends), and also where Clearsight worked and lived when she was hired as Queen Vigilance's private seer.
The palace has many towers, including the Royal Tower that Darkstalker showed Fathom and Indigo. The hallways are described by Indigo to have made of black marble with mirrors every three steps. The guest suite that Fathom stayed in had a large black door that is described to closely resemble many of the other doors in the palace. There was also a fountain in the corner of the room, and the room was lit by several candles. The SeaWing guest chambers were decorated with sea foam greens and blues, so the NightWings may often receive diplomats.
The throne room has central a dais that holds the queen's throne. It is possible that NightWing court members, including the queen's top seer are often present, though this is not proven.
The palace has a library, and this is where Clearsight spent most of her time calculating possible futures for Queen Vigilance. The walls of the library are presumably made of black marble like the rest of the palace. The library also has a librarian's desk. While she was working in the library, Clearsight filled up seemingly hundreds of scrolls, and it is described that dragons had to wade through the scrolls to get anywhere in the library.
Anemone also found what was most likely The Soul Reader, and threw it into a fountain.
The Palace is made of Black Marble, Columns, Pillars, and has a red roof, with many floors, courtyards, fountains, gardens, and is described as massive, and imposing by Qibli. Currently, It is described as runned down, and is more intact than a lot of ancient structures.
The Palace in map view seems larger than most palaces.