You create a circle on the
floor or other horizontal surface that teleports, as
greater teleport, any creature who stands on it to a designated
spot. Once you designate the destination for the circle, you can't change it. The spell fails if you attempt to set the circle to
teleport creatures into a solid object, to a place with which you are not familiar and have no clear description, or to another plane.
The circle itself is subtle and nearly impossible to notice. If you intend to keep creatures from activating it accidentally, you need to mark the circle in some way.
Teleportation circle can be made permanent with a
permanency spell. A permanent
teleportation circle that is disabled becomes inactive for 10 minutes, then can be triggered again as normal.