As I tried to search for an object, building, space, or place that was a good design for all, I realized that there cannot be just one specific item or place; this especially applies to an object. I feel as though an object that would be a good design for all could be literally anything, from a chair to a laptop, or a pen to a window. A chair is a place anyone can easily relax and take it easy while working on a laptop, playing a game or going through old pictures. Just the same, anyone can sit in front of a window to admire the view while writing a letter or simply doodling.
The same speculation applies to a building, space and place because it is difficult to just pick out one, or even a number of, places and spaces that could be a good design for all.