Heaven

Scooby visits Heaven in Operation S.C.O.O.B.Y after being killed by the Kaiser. Here he has an epiphany and returns to Earth ready to fight. As you can see on the map to the right of this text, Heaven is sparse and has few locations. It also (like Hell) incorporates some Greek mythological references (such as Elysium)

The Expanse is where Scooby first appears and where he speaks to the Entity. It is a white infinite place, seperate from time and space.

Elysium is where Scooby appears after speaking with the Entity. He makes his way through the thick grass, reeds, and trees and finds his way back to Earth.

The Stream of Oceanus is the entrance to Heaven and even though it wasn't seen, Scooby would have theoretically passed it after making his way through Elysium.