This radar view of the southwestern edge of the bright region on Titan known as Xanadu was captured by Cassini during the "T44" flyby, conducted on May 28, 2008. Xanadu is hilly in comparison to the smoother, darker plains adjacent to it, and is cut by numerous sinuous valleys that are likely to be river valleys. A couple of these river valleys exit Xanadu in unusually bright channels atop the plains.
Here is a detail of the brightest river:
NASA / JPL-Caltech
A bright river on Xanadu's southwest
In this Cassini RADAR view captured on 28 May 2008, an unusually bright river valley exits the Xanadu region to the north.