I was recently reading a fascinating book called the Devil in the White City by Erik Larson. The historic information led me to Google map the area to see what remained of Chicago's 1893 World's Fair: Columbian Exposition. The Chicago Columbian Exposition was, in large part, designed by Daniel Burnham and Frederick Law Olmsted. Most of the buildings were based on classical architecture. The area at the Court of Honor was known as The White City. The buildings were made of a white stucco, which, in comparison to the tenements of Chicago, seemed illuminated. It was also called the White City because of the extensive use of street lights, which made the boulevards and buildings usable at night.
Read more about it here.
I found that caches were already in place in this area, but I also found this very interesting item... an airplane was caught flying across the sky, creating a cool rainbow streak. I felt this airplane needed a cache placed in it's honor.
After asking a few friends about the possible placement, one was nice enough to scout out the airplane's actual location (thanks to you Walt), but in order to maintain the cache, I felt it should be closer to home. Then I discovered another "White City" nearby that was actually built to resemble the architecture of the Chicago World's Fair. It seemed an appropriate spot for a cache.
To find the cache, determine the location of the rainbow airplane's nose and use the green geochecker below (accurate within 30 feet) which will tell you the location of another Rainbow Airplane in a White City.
Final location closes at dusk.
Con g ratulations to Sgauss on his ftf!
You can validate your puzzle solution with certitude.