Within-Without is in Canberra, Australia and is Turrell's only Skyspace in the Southern Hemisphere. Unlike other Skyspaces, it's not inside a gallery and is unstaffed and free, so you have complete autonomy to come and go. The James Turrell house in Japan notwithstanding, I don't believe there are other Skyspaces where you can attend the dawn and dusk programs on the same day, or the dusk and dawn programs on the same night. The seat is heated too!
Ever Wondered Why Popcorn Is The Default Movie Theater Snack?