The John G. Shedd Aquarium's 5,800 square foot central rotunda was originally the brightest space in the aquarium. In 1970, walls were painted a dark, dismal green and the laylite was painted black, blocking all of the daylight from above. The Rotunda then became the Aquarium's darkest space.

The rotunda and tank were renovated to restore the hall's original architectural splendor and revive the tank's habitat. Laylite panels were replaced with new translucent panels and backlit by fixtures hidden above. New architectural lighting showcases the detailing of the coves, columns and historical artifacts of the space. Dynamic lighting "modes" – sky, rainforest and water – cycle throughout the day and promote the "connectedness" theme of the exhibit.