The angel Ezra revealed a sigil exists, that when drawn, will open a direct portal to Heaven. The portal is apparently in the image of Metatron's Cube, however it is unknown if Metatron or God made it in the first place.
In Reichenbach, we see the sigil drawn, but there was no portal. By this, it is implied that there is an incantation or ritual to open the portal. Fallen angels, who no longer have the ability to fly, used this door to return to Heaven under Metatron's leadership. Following Metatron's imprisonment, the gates remain closed, while the angels have reclaimed Heaven. After the events of Inside Man, the angels moved the portal somewhere else as revealed in Out of the Darkness, Into the Fire.
In The Future, it was revealed that a human passing through the portal would instantly kill them and return their matter back to the universe while their soul ascends to heaven.
In Funeralia, Castiel discovers the portal only lightly guarded by an inebriated Indra. Its shown that in lieu of an angel actively preventing use of the portal, one merely needs to enter the sandbox the portal is located in for it to activate and transport the user. After Castiel discovers the true state of Heaven, he returns through the portal with Naomi who states that it will be sealed until the situation is resolved one way or another. After the portal closes, Castiel picks up some of the sand from the sandbox and lets it run through his fingers.
- Season 9
- Season 10
- Season 11
- Out of the Darkness, Into the Fire (mentioned only)
- Season 12
- Season 13
- Despite the fact that Efram and Jonah stated the portal to have been moved in Out of the Darkness, Into the Fire, the location is shown to remain the same in later episodes. No explanation is ever given for this discrepancy.
- Curiously, no one ever appears to be in the park the portal is located in except for the angels guarding and using the portal.
- In Funeralia, Castiel calls Indra guarding the portal Indra guarding the Gates of Heaven. Before closing the portal, Naomi also states that the Gates of Heaven will be closed, suggesting that the portal is now considered the Gates of Heaven due to its function.