The spiral tower is just like it sounds, a giant towering building that is as large as a mountain...
However despite its appearance, only one part seems to be used when anyone visits. The main doors and entrances into the tower go into tunnels, well appointed and nicely lit, but merely lead to the small portion that serves as its underground foundation. Lit by unseen sources, the place is bright and warm. The closer you get to the center, the warmer and more humid it gets and the walls themselves are some odd material that defies most reason. There are weird snaking corridors everywhere, most lead to the center. The rest lead who knows where, a long red carpeted area the only place you can garganta in. (Other than the floors other Espada live on)
Shinya, the Tricera, lives in the Tower on his own sets of floors, which would allow gargantaing where he pleases.
Luca, the Septimo, also lives in the Tower with his own sets of floors, which too allow Gargantaing.
The center is a huge hulking inner dome, filled with doorways leading out and a large warm indoor bath and her living area. Her areas in this dome are sectioned off by movable walls except for one spot where she keeps some sort of force field to keep water and humidity out for her DDR machines.
The bath itself is a work of magical sciency art. Surrounded by tiles and sections for hiding bathers if they so wish, as well as quite a few bathing requirements such as soaps and towels (As well as a few lounging seats made of soft almost stone with cushions and tables) the bath contains off columned fountains that sit up out of it, though they magically move at times due to Sarai's wishes. The Bath itself can be altered to make tons of smaller ones for more personal greetings or can be a huge Carpathian Sea styled one.
Sophie's garden is nearby as well.
At the top of the spiral tower, which looks pointed from any angle but straight down at it, there is a large flat space that holds merely a lounge couch and nothing else. Thought wind should blow that high up, there is no air movement.