- how much design work was put into it. So many of it, from little bits and bobs (an awning, an electric socket, a doorframe), to the overall layout are unique to the area they are in and aren't copy-pasted elsewhere! It creates a coherent, but varying ensamble that is vibrant and alive, and is not just a grid of repeated elements.
- relatedly, how deeply organic the maze of the Barbican is. Contrast the raw concrete of the Barbican with the flowing lines of the Walkie-Talkie: one has an organic and smooth shape, but is really a 3D grid of repeated blocks; the other is made entirely of exposed raw concrete, but you never know what you will see around a corner. In this sense, the Barbican is more organic than most modern architecture. It's a place of wonder and surprise.
I love the Barbican.