I checked this out in Google Mars myself and the thing is there at the coordinates given. Is it a structure? It sure looks like one. However, we must consider that even on Google Earth, the application is prone to anomalies here and there, showing "artifacts" that aren't really there. So that is a possibility. Yet Google Mars is based on NASA satellite photos of the planet. If it is a structure, it appears to be in a good location for one -- what looks like a smooth, crater-free plain. What's needed is a high-resolution image of the site. What do you think?