Exxopolis is part bouncy castle, part space-age church.
A group called Architects of Air designs the inflatable structures called luminaria and installs them in cities around the world. Each one is slightly different to meet the needs of its location.
Daylight shines through specially designed plastic that comes in four different hues -- green, red, blue and yellow.
Sunday, September 15th is the last day to visit the inflatable experience in Grand Park downtown.