The Caltrans District 7 Headquarters building at 100 South Main Street in Downtown Los Angeles, California, United States serves the California Department of Transportation (Caltrans) and the Los Angeles Department of Transportation. Built on a $165 million budget, it opened on September 24, 2004. Its futuristic and environmentally friendly design won its designer, Thom Mayne, the 2005 Pritzker Prize. The design and construction of the building was documented across four episodes on the History Channel series Modern Marvels, to demonstrate the unique challenges presented in the design and construction of large buildings over the past two centuries.