Land of a 1000 Doors

From the introduction:

The Land of a 1000 Doors is a module set in the world of Eostros. It is designed as the sequel to In Search of Kelandor's Gold, Judges Guild product number 1170. However, the module can easily be played independently and set into any campaign. The Desert of Storms is a northern desert across Teslor’s Mountains. Players will start the adventure on the southern side of the mountains in the capital city of the Kingdom of Palos, Pierreville. For those who are familiar with In Search of Kelandor’s Gold, Kelandor’s castle is in the southern part of the kingdom, while Pierreville is in the northwestern part. The current king of Palos is King Carlanges.