The Commonwealth of Massachusetts has a total of 189 National Historic Landmarks (NHLs) within its borders. This is the second highest statewide total in the United States after New York, which has 256. Of the Massachusetts NHLs, 58 are in the state capital of Boston, and are listed separately. Ten of the remaining 131 designations were made when the NHL program was formally inaugurated on October 9, 1960; the most recent was for the Brookline Reservoir of the Cochituate Aqueduct in Brookline in 2015. Cambridge is the city with the most NHLs outside Boston (at 19), and Middlesex County is home to 43 NHLs (again outside the 58 from Boston, which comprise all but one of the NHLs in Suffolk County).