This image covers a 26-kilometer-wide impact crater northeast of the Hellas impact basin. The crater exposes large blocks of bedrock (called "megabreccia") in both the central uplift and in the walls of the crater.
The enhanced-color subimage from the wall shows a large, approximately 250-meter-wide reddish block, although actually "red" in the infrared-shifted color of HiRISE. These blocks could be ejecta from the ancient Hellas impact or other large impacts from billions of years ago.
Image credit: NASA/JPL/University of Arizona
Note: For more information, see PIA18226: A Big Block of Red Bedrock.