Combine Overworld

"“For the Combine Overworld, our new home.""

- - Wallace Breen

The Combine Overworld is apparently the Combine's original homeworld. It can be assumed that the Overworld is the primary world from which the Combine launch their invasions of other worlds, though this has not been confirmed. However, it is not a planet for some reason.

Appearance
The Combine Overworld's climate seems to be different from that of Earth. From what can be seen through the portal, the orange sky appears gaseous and intangible; strange clouds and even what look like stars can be seen, bearing an appearance similar to that of Xen. It is the smallest known universe and about the size of the Whirlpool Galaxy. It also has the Combine symbol on it.

History
In 2039 of the 21st century, the Combine Overworld was discovered by Aperture scientists and NASA scientists with a galactic technology detector that is 100,000km light-years away from the Milky Way Galaxy.