Celestia

The Seven Mounting Heavens of Celestia is the Lawful Good plane in the Great Wheel cosmology. It is a single mountain surrounded by a sea of holy water called the Silver Sea, and travelers to this plane will always find themselves arriving on the beach. The plane is populated by generic lawful good creatures, such as Solars, Aasimars, Devas, and Bahamut. In order to go from one layer to the next, you have to scale that section of the mountain. Of course, the mountain is a metaphor for something, as there are multiple paths but only someone who is "truly just and good at heart" can ascend the mountain. Naturally, this means that the DM can deny you access to any layer above the first by citing that one puppy you kicked or that time that you stabbed a villager back when your character was dominated by a vengeful wizard. Of course he could be even more of a troll and let you ascend to the seventh layer, Chronias, from which there is no return; you either transcend and become part of the plane or you did a bad thing once and whatever's up there murders your soul forever and erases you from the multiverse.