We just did the tour of the huge southeast wastewater treatment plant...
Having toured the sewers of Paris, this was a lot better (and a lot less smelly.) I forgot my camera, but Mo took some phone pix and I'll try to get them. Urban infrastructure is interesting.
The plant is cool, super clean and organized, barely a spec of rust visible anywhere. The older buildings are industrial Art Deco, full of doodads and glass bricks and cream and peach colors.
It's been noted that sewage treatment has saved more lives than medicine.