I work right over there and I've worked right over there for over 10 years. So I'm not sure why I haven't wandered by here earlier. Once I found this circus/carnival/playground I knew that I had to direct other people here as well.
On my last visit, a very friendly gentleman pulled up and proceeded to take groceries out of his car. He stopped to chat for a bit. I mentioned that I had noticed these when I was walking by and just had to stop. He laughed and said that he needed to touch some of them up. Yep, he's the artist. He does metal working when he's bored. He said that he and his wife sat on their porch for over 20 years looking at the naked guy wire (yeah, I learned a new word that day) and he decided that he saw people on that wire. So he went about to make that vision a reality.
The cache container is located a few blocks away. The location of the final is:
N38 57.D8C W077 03.8AB
A = (the number of figures on the rusted colored guy wire cover) x 2
B = the number of discs the plate spinner is spinning
C = (the number of letters in the first word of the note on the guy wire cover) + (the number of letters in the last word of the note on the guy wire cover)
D = (the number of rungs on the ladder that the figure is climbing) + 2
Once you reach the final, you're looking for a nano. Both stages are accessible 24/7 but it would be difficult to enjoy all of the metal figures (especially the ones higher up) in the dark.
You can check your answers for this puzzle on GeoChecker.com.