Good King's castle

The Good King's castle is the central location of the activities of The King, Sir Johan, Peewit, Princess Savina, and Dame Barbara. In mainstream Smurfs media, it first appeared in the Johan and Peewit comics, and then later appeared in the animated version of The Smurfs And The Magic Flute and the Smurfs cartoon show.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, it is referred to as King Audric's castle, first appearing in "The Magic Flute With Six Holes".

Hero: The Guardian Smurf stories
In the HERO: The Guardian Smurf story series, its likely first appearance is in the story "Wonder The Naughty".