I got to see Biosphere II about 20 years ago. At that time they were still running experiments but there were no people living in it. Interesting stuff, but the little amusement park kind of thing they were trying to run around it was pretty sad.

What I remember most is the ants - they were everywhere. Long lines of them crawling on the inside of the glass.

They've built quite a few new structures since I saw it. Worth seeing if you are ever in Tucson.



The Lost History of One of the World's Strangest Science Experiments

That is fascinating.