The Moon

Termina's moon,Teminus. It was stopped from falling on Clock Town by Link

Majora's Dimension
Inside of the moon lies a pocket dimension in which Majora was Imprisoned. The dimension resembles a large grassy field with a tree in the middle. Several miles away from the tree is a settlement of Moon Children. Majora is buried in a casket under the tree.

During Majora's Mask
After Skull Kid was possessed my Majora's Mask,he used Dark magic to summon the moon closer. It fell after three days,Link used the Ocarina of Time to restart the time. He defeated the four bosses then freed Skull Kid from The Mask. The moon was sent back to where it was