The High Bridge is part of the Old Croton Aqueduct, the brick water conduit that brought New York City its earliest supply of clean water. The bridge is listed on the National Register of Historic Places and is a New York City landmark. As part of the Old Croton Aqueduct, considered one of America’s greatest 19th century engineering achievements, it shares the Aqueduct’s designation as a National Historic Landmark. On Earth Day, April 22, 2007, Mayor Bloomberg launched PlaNYC and announced that the High Bridge would be restored and reopened.