This sprawling look at the martian landscape surrounding the Mars Exploration Rover Spirit is the first 3-D stereo image from the rover's navigation camera. A surface depression nicknamed "Sleepy Hollow" can be seen to center left of the image. Scientists theorize that this topographic feature, measuring about 10 meters (30 feet) in diameter and located approximately 10 to 20 meters (30 to 60 feet) away from Spirit, is either an impact crater or a product of wind erosion.