Portal

Cast (Action) (Persistent, Up to 8 Hours): You touch a flat, unoccupied, solid surface and magically trace a Huge or smaller doorway upon it. The doorway faintly shimmers with extradimensional energies, but it is otherwise dormant until you trace another one.

If you create two doorways of identical size, they become linked. While the doorways are linked, anything that moves through one exits via the other, as if the spaces in front of each doorway were adjacent. The doorways admit light, sound, temperature, and other forces, which means that a creature looking into one doorway can see out of the other. While the doorways are linked, you can't create more.

Closing a Doorway: When a linked doorway disappears, either because 8 hours have passed or you have used your action to dismiss the spell early (see Spell Durations), its counterpart becomes dormant until you create a replacement for the doorway you closed.

Obstructions: When a doorway closes, any creature or object crossing the threshold is ejected to the nearest unoccupied space. An ejected creature is paralyzed until the end of its next turn. If the threshold closes between a grabbed creature and its grabber, the grab ends.