The Detroit Institute of Arts (DIA), originally name the Detroit Museum of Art, has one of the largest, most significant art collections in the United States. In 2003, the DIA ranked as the second largest municipally-owned museum in the United States with an art collection valued at more than one billion dollars. With over 100 galleries, it now covers 677,000 square feet (62,893 m²), a major renovation and expansion project completed in 2007 added 77,000 sq. ft. (7,153 m²). The museum building itself is highly regarded by architects. Its original building, designed by Paul Cret, is flanked by north and south wings covered with a white marble exterior. It is part of the city's Cultural Center Historic District listed in the National Register of Historic Places.