A “palatial” apartment that soars over  Los Angeles  from its prominent perch at the top of one of the city’s most iconic high-rise buildings has  hit the market  for the first time in more than 50 years, having previously served as the home of two of Hollywood’s most prominent archivists. The property, which is located in the  storied Sierra Towers building  on Doheny Road, is composed of  three  units inside the enormous midcentury modern skyscraper, which was designed by architect  Jack A.