In the series finale, "Come Along With Me," the original Tree House was destroyed by a monster summoned by GOLB. Following the battle, Fern (the Grass Finn) passed away and left behind a small seedling shaped like the Finn Sword.
The Tree Fort's story begins centuries before Finn and Jake were even born. In a past life, Finn was a girl named , a thief hired to steal Princess Bubblegum’s amulet. After falling into a radioactive river and losing her life near the Candy Kingdom, Shoko’s body was buried where a small sapling grew. That sapling was literally "fertilized" by her remains, eventually growing into the massive, hollowed-out willow tree that would become the Tree House . The Marceline Era Adventure Time Tree House (Tree Fort)
Before Finn and Jake moved in, the Tree Fort was home to and her then-boyfriend, Ash. They lived there for quite some time, which is why the house is filled with musical instruments and why Marceline technically "owns" the property. When Finn and Jake first encountered her in the episode "Evicted!", she reclaimed her home, forcing the duo to search for a new place before eventually letting them keep it. Life Inside the Fort In the series finale, "Come Along With Me,"
An abandoned jail cell, a demon-summoning vault, and even an entire civilization living within the walls. Destruction and Rebirth In a past life, Finn was a girl
Take a deeper look at the secrets and hidden history buried within the walls of the Tree Fort:
Often shifting between the second and third floors, home to BMO and Jake’s cooking.