"Louisville Letter Play" is a series of 20 2'x4' metal and ceramic panels lining the South Street Pedestrian Underpass.

Created by Louisville artist Gregory Fields, the shapes spell out "Louisville Colorado US" in playful metal and clay forms. The steel panels are designed to gradually patina until they match the rust-colored railroad bridge overhead.

The piece was installed in summer of 2021, and was generously funded by the City of Louisville through the Louisville Cultural Council.