I have a river home and place the fire ring on river bank under some big cottonwood trees.  We have had so many lovely nights under the stars sitting around our fire circle. Example, on Xmas, the first full moon in many years and a guitar and beer and marshmellows.  It was memorable.  We had bad flood a couple of weeks ago (+34 feet) and my ring was totally under swift water.  But it is still in place and ready for the next celebration.  

Pros: Perfect size, easy to set up and incredibly durable
Cons: none