Manifest Zones

Manifest zones are certain locations on Eberron that share a particularly close connection with one of the thirteen planes that orbit Eberron. Within a manifest zone, the area takes on properties of that plane; for instance, a manifest zone to the plane of Risia, the Plain of Ice may make the area much colder than under normal circumstances. Manifest zones also allow passage between one plane and the next; though for some zones this may only be a one-way trip.
The effects of a manifest zone may be related to a plane's proximity to Eberron. For instance, the effects of a zone may grow stronger as the plane approaches Eberron, or grow weaker as the plane grows more distant. However, even at a plane's most remote location, a manifest zone still has great effects on the world.
Manifest zones may be located in the air, in the ground, or even deep within the Khyber. Manifest zones, are extremely long lasting, if not permanent; though it is remotely possible for an old zone to disappear and a new zone to appear. Zones can also range in size from the small (encompassing a city block) to the larger (encompassing a large forest). The locations of these manifest zones do not follow any scheme and scholars have failed to detect a pattern to their location.
While once manifest zones for all thirteen planes existed, now manifest zones only exist for twelve since the Cul'sir giants severed the plane of Dal Quor from Eberron.
About ten thousand years ago, the Gatekeeper Druids developed a way to seal off a manifest zone during the Daelkyr War. They developed dimensional seals (or Gatekeeper Seals), which magically lock down the effects of a manifest zone. All of these seals, however, were designed to lock down manifest zones to Xoriat, and the magic to produce them was lost to the ages.