A suggestion :
Maybe the Sech nevali monastery in Varisia unchained between three mountains on the top of an inversed mountain ?
In my mind, it is a thassilonian ruin created by the first emperor Xin in three days.
Inside is a demi plane. A shelter for the Cabale, one of the most and ancient organisation of Golarion.

Characters and Dragons from How to Train your Dragon

Critters from The Dark Crystal (Jim Henson's movie)
Characters from the obscure, mildly average Pathfinder and Outlander movies (vikings)

Labyrith's Goblins and the Goblin King (Jim Henson's movie)
Cowboy Beebop cast
Evas (Evas only!)

-Mayor Kusanagi in a Fuchikoma (Ghost in the Shell)
-Jin and Mugen (Samurai Shamploo)
-The faun (satyr?) (from Guillermo del Toro Pan's labyrinth)
-Hellboy cast (Hellboy, Liz Sherman, Abe and Roger)
-Steam Punk characters
-US civil war and pre-civil war characters
-Sci fi robotic armor and soldiers