Egg Mannonen's Steamed Custard is an incredible build on an area that is only one sixth of a sim - 9000 square meters, and 2000 meters up in the sky. Many things rotate and move here, including atmospheric debris, smoke, and moving gears. Although the build is called Steampunk, it is also reminiscent of mainstream science fiction - one of those huge rusted Empire warships comes to mind in Star Wars.
You can rent a house and live at Steamed Custard (if any are available). It is a great place to walk around and admire the effort and love put into the design of the build.
To visit Steamed Custard: