4D-3 is a planet that is covered by an atmosphere made of water.
Despite having a thick liquid atmosphere comprised of water, the surface of the planet is similar to the Earth's. Unlike other stops along the Galaxy Express 999 line, 4D-3 doesn't have a physical station due to laws on the planet that restrict buildings and structures that would greatly alter the natural environment.
| Location Name | 4D-3 |
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| 1st anime episode: | Galaxy Express 999 #15 |
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