PBS did a special on it not long ago: http://www.pbs.org/lifebeyondearth/alone/mars.html
It is an area recently explored by the Opportunity rover comprising a basin and hills. The importance of a basin is the shelter the surrounding hills provide when the winds get nasty. Water is believed to be close under the surface.
If you go to Goigle Mars and search for Eagle Mountsin, you can see the area.
If I had to live on Mars, this would be the place. Oh , and the Opportunity river plays a major part in the book, I Choose Mars!