The Garden Wall is the titular wall in the series, which Greg and Wirt jump over in the flashback's from the chapter, "Into the Unknown".


When Greg and Wirt ran from the police officer on Halloween night, they climbed up a tree and sat over a wall. The officer told them to climb down so they wouldn't get hurt, but they thought he actually wanted to arrest them for hanging out in the cemetery.

When they climbed over to the other side, Wirt scolded Greg for getting them into trouble. Wirt was interrupted when a train came pulling down the tracks on which the siblings where standing. They jumped off the tracks to avoid getting hit, but found themselves endangered again as they fell into a lake. This began their journey into the Unknown.

Song References

Jason, in the song of the final episode and the song in Chapter 6: Lullaby in Frogland, sings about the Garden Wall in the theme of the show that shares the same title. The final verse is as follows:
Over the treetops and mountains

Over the blackened ravines

Then softly it falls by a house near a stream

And over the garden wall

To thee