The entrance hall of this Abu Dhabi villa is organised around a single vertical object. A cylindrical aquarium rises through three floors, and the stair winds around it rather than beside it. You climb the house by walking around the water.
A stair built around a tank
The engineering question came before the aesthetic one. A tank of that height carries a great deal of weight and needs filtration, lighting and access that nobody is ever meant to see. Those requirements set the diameter of the drum, and the drum set the radius of the stair.
Jellyfish, and why they suit the job
Jellyfish move slowly and read well in silhouette, which is what you want in something viewed from three different levels and from every angle as you turn. Lit from above, they carry the light down through the water and into the hall.
