Akris' Portal (11th level spell)

You conjure a portal linking an unoccupied space you can see within range to a precise location on a different plane of existence. The portal is a circular opening, which you can make 5 to 500 feet in diameter. You can orient the portal in any direction you choose. The portal lasts untill dispelled (dc 28)

The portal has a front and a back on each plane where it appears. Travel through the portal is possible only by moving through its front. Anything that does so is instantly transported to the other plane, appearing in the unoccupied space nearest to the portal.

Deities and other planar rulers can not prevent portals created by this spell from opening in their presence or anywhere within their domains