The Tombstone of Dead Leaves is a stop along the Galaxy Express 999 route.
The Tombstone of Dead Leaves is one of the few stops on the Galaxy Express that isn't actually a planet. As the name suggests it is an area of space that is literally composed of dead leaves.
The area was originally a planet covered in massive trees but it was eventually destroyed. All that currently remains are the dead leaves that have formed a ring and orbit around where the planet once was.