sentences:  On April 24, 1973, at the request of Una Walker, H. Alexander Walker's widow, the house was added as site 73000665 to the National Register of Historic Places listings in Oahu and listed as a "valuable historic property" by Hawaii Historic Places.Una Walker maintained the estate by making the grounds available for weddings and visitors and as a movie and television set.It appeared in many Hawaii 5-0 and Magnum PI shows.