This is a rare opportunity in a top Riverside Drive building to join two apartments with spectacular Hudson River views West and North and bright, open city views South and East through oversized windows from thirteen rooms. One senses a rich architectural heritage as you step from your own private elevator landing through the original bronze mirrored doors into a spectacular riverview mansion in the sky!    Here exists an unprecedented opportunity to create an unrivalled thirteen room, five bedroom home on a high floor in one of Riverside Drive's most prestigious full-service cooperatives.  When restored, this very special home will become one of the most remarkable apartments on Riverside Drive.  Old world European elegance abounds in its ten foot ceilings and turn-of-the-century details including wood-beamed ceilings, wainscoting, mahogany French doors, and two decorative fireplaces.  This apartment is one-of-a-kind, huge, and offers a flexible layout with many options.  This fine residence was built in 1909 by famed architect William Rouse who designed many of the homes found on Riverside Drive as well as Fifth and Park Avenues.  Located on a hill on Riverside Drive, in an elegant, yet centrally located neighborhood, in the heart of the Upper Westside, convenient to schools, shops, restaurants and all transportation.