Golarion: 300 ARA
Interplanar Railway System
The Interplanar Railway System, or Interail, is the primary means of long distance travel in Golarion, as well as between planes. It is a network of permanent demiplanes with gates to important locations, with rail lines between them. The System is operated by the Empire.
Interail grew out of the planar connections established by Tamuril, and their use for travel. As traffic grew, she created a dedicated demiplane. After the publication of the Davenian Theory of Permanent Portals, the network was expanded and traffic grew even further. To handle the increase, gnomish engineers provided tracks with magically propelled trams, modeled on dwarven minecarts. Eventually the Empire took over management, and created a vast network of interconnectivity.
Grand Central Station
At the heart of the Interail system lies Grand Central Station, the nexus of all traffic. A large demiplane built on several tiers, it provides the primary place to change trams. Artwork of many cultures from across the planes fill the station. Smaller stations connecting to various regions route traffic to and from Grand Central Station.