Hidden design staircase

Quick answer：

Hidden design staircases are architectural features that are designed to be discreet and blend seamlessly into the surrounding space. They often incorporate innovative design elements to remain unobtrusive while still providing a functional and aesthetic element to a building. Examples include staircases that are integrated into wall structures, concealed within bookshelves, or designed to appear as part of the floor or ceiling. These staircases are particularly popular in homes with limited space or where a minimalist design is desired.