 Five years later, Nationals Park built off Cincinnati's design, making yet more liberal use of glass along with white concrete that would not clash with architecture in the District.Nationals Park became the first stadium to go green while still offering all of the amenities — another concept that looked ahead instead of behind.The retro-modern style climaxed in 2010 with the sculptured, contemporary exterior and canopy of Target Field, rendering it almost unrecognizable from the outside.