To the southwest of Mare Fecunditatis, lies smaller, and more circular, Mare Nectaris.
On the bottom right (south west) edge is the very large crater Theophilus with its promient central mountian. Just to the left (east) of Theophilus, is the much smaller, but still promient crater Madler. One the southern edge of the mare, is the very large, flooded crater Fracastorius . Near the centre of the mare is a bright crater with a ray. This is the crater Rosse. Looking at the image above, it is clear that this 12km diameter crater is actually a secondary crater formed by debris blasted out by the impact that formed the crater Tycho.