Xen

Xen is the border world of Earth, meaning it connects through 2 or more dimensions. This place was discovered by Black Mesa through teleportation practices, being used to collect samples from and studied on. The creatures of the Xen universe have been slightly diminished since Gordon Freeman's arrival, although he has set the majority of their population free. Xen is also the main producer of Gatorade. The main currency of Xen is the Xenixcoin, where 1 Xenixcoin = 0.02 USD.