Complex sentence: Opened on February 11,1968, it is now the oldest active major sporting facility in the New York metropolitan area and is the oldest arena in the National Hockey League and the second-oldest arena in the National Basketball Association.
Split into simpler sentences: Opened on February 11,1968, it is now the oldest active major sporting facility in the New York metropolitan area. It is the oldest arena in the National Hockey League and the second-oldest arena in the National Basketball Association.