From publisher blurb:
This book presents a number of magic items suitable for use exclusively in structures. Unlike most magic items, these creations are generally not portable, being constructed into the fabric of the building itself. The items are divided into the following categories:
Archways
Doors
Floors
Locks
Statuary
Walls
The ebook contains 44 new magical creations that are suitable for lairs and buildings of all kinds. Though player characters can freely make use of these items, their primary purpose is to protect and make strongholds safer for their inhabitants.
Wondrous Creations 4: Lair is a volume of magic item sourcebooks compatible with the Pathfinder Roleplaying Game and suitable for GMs and players of any level.