Sustain Gateway

5-level Conjuration

Touch a portal either naturally generated (such as an elemental vortex) or created by a spell (such as Teleportation Circle, Arcane Gate, Gate, etc.) For the duration of the spell, as long as you continue to touch the portal, it remains open and connected to its duration. If you cast this spell while concentrating on another spell that opened said portal, the portal doesn't close before touch it.
At higher levels: If you cast this spell using a spell slot of 7th or higher, its duration is concentration, up to 10 minutes. If you use spell slot of 9th level, its duration is concentration, up to 1 hour.