Here is a photo of the underwater viewing room in the Environmental Discovery Center at Indian Springs Metropark. It is an acrylic cylinder with a domed roof, and an arched walkway leading from the basement of the building. Here is a photo of the pond behind the center, with the underwater viewing room visible as a light spot in the pond.
Wanting somewhere to wander, Danielle and I headed over to the park this afternoon. Everything was going well until we tried to head down some of the nature center trails which were much more insect infested than we would have prefered. I had numerous deer flies on me at any given time, and one of them bit my head. Of course there were also mosquitoes. Lots and lots and lots of mosquitoes.
(This photo was taken with a Peleng 8mm fisheye lens and is posted without cropping or other processing. I personally find it interesting how well a lens like that works for photographing the inside of a curved room. I feel that defishing and/or cropping would have made it less interesting.)