Endymion (76 miles wide) is a grand crater visible 3 days after the new Moon. The floor is flooded and dark. Its very high walls rise in some places to 2.5 miles above the lava floor. In a 6 inch refractor you will see very little relief on the floor. Catch this great formation on the third day after the new Moon. Be sure to show Endymion to others if you are at a public star party and a thin crescent is hanging in the western sky.
Atlas (53 miles wide) is a great formation and is about 1.7 miles deep. There is a small central peak that is a little off center, perhaps less than half a mile high. The high walls are terraced. Best observed about 4 days after the new Moon.