I think you're asking about the moon's "mares," which are broad, relatively smooth plains on the lunar surface. The word "mare" is Latin for sea, which is what early astronomers mistook the plains for.
Maria
There is a crater on the moon.
This is known as an impact crater. Please see the related link.
The South Pole-Aitken basin (not "Aitken crater") on the far side of the moon, at 1,600 miles across, is not only the largest known impact crater on the moon but one of the largest in the solar system. It is also believed to be the moon's oldest and deepest (over 8 miles deep).
mountainous crater regions and the light colored ray systems of a few impact craters
There is a "Herschel Crater" on our own Moon; on Mimas; and on the planet Mars.
This is known as a crater.
The cheese crater. The cheese crater is the cheeseiest crater in all of cheese land.
The large flat areas on the moon are called "Maria" (Latin for "seas", because the early astronomers thought that's what they are). They are huge regions of smooth rock. If very dark, they are so by being in shadows. Smaller dark spots are meteor-impact crater floors in the shadows of the crater wall.
There is a crater on the top of a moon and a volcano.
Alcatzervater Crater
a crater