The Horned King's Castle was once a defining landmark of Prydain and was one of the most feared places in the world since it held power unlike any other, especially since it was raw power from the ancient First Cartoonian War. It was ruled by the Horned King, and it's residents were nothing but thugs and barbarians, as well as two dragons and the Horned King's assistant, Creeper. This is where the Villain League had felt like they were in the golden days of evil during the times of the Second Cartoonian War, and it was where the last revival of Cobra took place, though quite non-purely. However, after the Black Cauldron was disarmed, the entire castle was dragged into The Banished Realms, along with the Horned King, and it now serves as Malefor's Fortress. Since there are still remnants of the dark power it possessed, the castle ruins were strictly forbidden by the High Council.