During the last part of the Reckoning, power was released on an unprecedented scale from the Ascension of the God Ramorge. As the world twisted and contorted it also absorbed a large amount of that energy in stones deep beneath the ground. Some of these stones, when collected and processed correctly, can form a Weyr Stone. These stones can create a link between themselves and previously prepared locations, thus allowing travel between them. Sadly the Weyr Stone has to stay where it was used and cannot be brought with. Several locations are linked in such a way that a permanent stone is in place to facilitate constant shipping and travel. There is no known limit to the range of the stones as some have been tested between the planes themselves and worked effectively.
One cautionary note though. While these stones represent an incredible amount of power, they are also rumored to corrupt users who spend to much time with them as the Dark Ones voice speaks to them and corrupts them until they are used up. The magic can be extracted but at a terrible cost, requiring at least five thousand souls to absorb the energy that must then be harvested in a secondary ritual prior to the souls exploding from the sheer force of the transfer. This ritual has been done once successfully. The results walk the land.