A great example of John Portman's work is the Westin Peachtree Plaza in downtown Atlanta. It is nearly identical to the Marriott Renaissance Center in Detroit.

Also 73-stories, 723ft. tall, and offers incredible views of downtown ATL. It appears to be taller, as the building sits in the middle of downtown at the corner of Peachtree Street and International Blvd, which I think is the highest elevation in the downtown area.

On a clear day, you can see for miles and miles. Views are to the north towards Midtown and Buckhead, south towards Turner Field and Hartsfield Intl, and east to Decatur and Stone Mountain. Lots of green treetops beginning just beyond Downtown/Midtown and extending forever.

Swift ride to the top in a glass elevator.

Though I have never been in the Marriott Renaissance Center, I cannot imagine that the view of the downtown Detroit skyline is overly impressive. However, it has been ten years since my last visit to The Motor City, so I may be incorrect in that assertion.