The $480 million, 40,000-seat Minnesota Twins ballpark was designed as a modern interpretation of the state's natural creations. Weather-resistant Minnesota limestone forms the mass of the ballpark's façade. Glass and metal details punctuate the limestone surface. HGA is serving as local architect on the project, which is planned for an eight-acre site in downtown Minneapolis. They are joined by lead design firm HOK+Sport, Kansas City, Mo. (which has designed 14 new professional ballparks), and local contractor M. A. Mortenson Co., one of the largest U.S. builders of sports venues.