D&D 3.0: Tales from Mystara
Magical Corridors are a fast and secure method of transportation provided by the Corridor Masters one of the Mysteries of Magic. Magical Corridors can transport people, creatures and goods along great distances. Is a very powerful advanced form of Dimensional Door spell. It can only be created, maintain and control by Corridor Masters. The minimum fee for using a Corridor starts with 10 gps per person and goes up. The rates depend on distance and the population of the city.
A Magical Corridor Plaza is usually located on the center of a city, near it’s marketplace and custom offices. Each city that is connected by the Corridor Masters has a store that is the Office of the Corridor Masters. The store is usually called “Corridor Plaza” or “Magical Corridor” and is adorned with an arch in front of the store. The corridors are opened on the location of the arch to control the flow of people.
Even when Corridor Masters can be forced to do so, they cannot open corridors in restricted places like inside castles or vaults. These kind of protections also block teleports and dimensional door spells. Protecting a location against corridors is possible using the right scroll. A scroll who are sold by the Corridor Masters only.
See the entry on Travelling Time for costs and times.