Buzz. Whrrr. Portal access *granted*! A steel door slides open into a vortex!
This is the new illustration for slip gate artificial portals for role playing games.
Here is an example of plotting slip gates on the same map.
A slip gate is an artificial portal created by engineering. Slip gates are powered like teleport pads, but can operate in a broader range of teleporting locations. A tele pad can only move one player character from one point on a low level map to another point on the same map. Slip gates can open to entirely other worlds, and due to their often having a data input peripheral or control panel screen, these teleport constructs can imitate elemental and primordial portals.
The slip gates in the illustration above indicate imitation of elemental and primordial portals.
In the illustration above we have several slip gates, and possibly a gas portal arrival point since there is an illustration of multiple players arriving at a point of reference. Each slip gate in this example has an alpha-numeric label, thus pointing to a reference on the portal router document. A second level is indicated by grated out and transparent backdrop grid.
Here is another map.
This map indicates a hydra portal. There is a one way arrival point indicated by a red spiral in the dead center of the map.
In the above illustration I am moving around objects in Visio. These objects indicate encounters. Encounters can be graphical icons, symbols, or alphanumeric callouts referencing a controlled document, usually the matrix document.
See Portals Manual ebook on Kindle to learn more about documenting portals.