The Chamber of the gems is located within the castle of Lireo, guarded by multiple Lirean Soldiers. Inside the chabber are multiple artifacts, including (formerly) the four elemental gems.
2005 - 2006
The gem chamber is where Mine-a used to keep her crown when she is not wearing it, as well as the four elemental gems when not in use. It is a room guarded by several soldiers. The space where the gems are kept is being surrounded by a wall that levitates whenever someone (presumably a Sang'gre or a Queen) commands it to.
2016 - 2017
The chamber is where Mine-a keeps the gems whenever she goes to sleep. It is also where the important treasures and items of Lireo are being kept, including the Setro ng Reyna, but it was separated and kept in a separate platform.
However, at some point during Danaya's reign the weapons such as the Setro ng Reyna and the sword of Mine-a have been moved out from the chamber and have been placed at the Lirean armory.