You must walk just over 360 degrees through the spiral to reach the center of Joe. The visitor arrives at a nearly circular enclosure. There is plenty of room but you might feel some panic about being able to escape over the high walls. (The museum staff won't let you bring in a grappling hook and rope.) Of course, the way you came in is still there but the space can give you the feeling of being trapped with plenty of space.
I looked through the archives and found one overeposed shot in which you can look down and see the overall shape. https://tinyurl.com/yyfx32ap