Article: The Detroit International Riverfront includes a partially completed three-and-one-half mile riverfront promenade with a combination of parks, residential buildings, and commercial areas. It extends from Hart Plaza to the MacArthur Bridge accessing Belle Isle Park (the largest island park in a U.S. city). The riverfront includes Tri-Centennial State Park and Harbor, Michigan's first urban state park. The second phase is a two-mile (3 km) extension from Hart Plaza to the Ambassador Bridge for a total of five miles (8 km) of parkway from bridge to bridge. Civic planners envision that the pedestrian parks will stimulate residential redevelopment of riverfront properties condemned under eminent domain.

Question: How long is the second phase of the riverfront?
two-mile