The Guardian's Tower is Shadow Guardian's Specially desinged defense tower
- Location: lone island in middle of land.
- Function: Multi-layered dungeon.
- Boss: Shadow Guardian
- History: Once, Shadow Guardian kidnapped Princess Bubblegum to lure Finn into a battle to test the latter's strength.
The floor can actually fall out from underneath when struck with a powerful blow.
Titanosaurus is the huge guard dog of the tower(more like guard lizard).