The Vorlon Homeworld is off-limits until we're ready...until we've earned the right to go there..." ...a million years from now.
– Lyta Alexander, 2262
The Vorlon Homeworld was home to the Vorlon race and capital planet of the Vorlon Empire.
Next to nothing is known about the planet, and the only non-Vorlons who are known to have been there and returned are
Sebastian and Lyta Alexander. 
Vorlon medical facilities on the homeworld
2261, after the Battle of Coriana VI, the Vorlons left the galaxy with all the other First Ones to travel beyond the The Rim.
Expeditions were sent to the planet following the Vorlons' departure, none of which survived.
Lyta Alexander has said that the Vorlon homeworld is "off limits" until the younger races are ready for the technology that is on the planet.
New Earth Edit
1,002,261, having evolved into beings similar to Vorlons, humans took up residence on the Vorlon homeworld, renaming it "New Earth" when Sol was induced to go nova by parties unknown.