"The Ducal Palace at Mantua, she said, contains a series of increasingly smaller rooms. They twine around the grand apartments, beyond beautifully carved door-frames one stoops to enter."
Camera picta, parete sud
Public DomainCamera picta, parete sud - Credit: Sailko
Camera picta, parete est
Public DomainCamera picta, parete est - Credit: Sailko

Tessier-Ashpool's maze-like Villa Straylight resembles the Ducal Palace at Mantua, in particular the Scala Santa or "The Apartment of Dwarves" a series of ever smaller rooms underneath the main apartments. 

The Apartment of Dwarves itself was a reproduction of the Scala Sancta in St John Lateran in Rome.