Return of the Bling
Here are a few more images that Pinterest threw my way. Apart from Jewish bridal rings, I did not know that rings in the shape of buildings were a thing, but here is an interesting selection.
I’ve thrown in a few thoughts about what these shapes might mean for magical rings in a fantasy game.
Note: All images are copyright their original owners, at the urls indicated.
The Castle
The castle is a symbol of safety and protection, so this ring might give its wearer a significant boost to armor protection, or protect in some more subtle way.
The Palace
The palace is a place of power and authority, so a ring in that form might give its wearer a boost to their social status and accompanying skills, making others treat them as powerful nobles even if they are not.
The Temple
Like the portable shrine ring from an earlier post, this ring might give the wearer the same protection as being on consecrated ground, or it might give their prayers greater efficacy, perhaps even granting limited clerical powers to a non-cleric.
The Tower
Towers are usually associated with wizards, so this ring might enhance a wearer’s magical abilities, possibly allowing them to cast spells at a higher level than normal or making their spells harder for targets to resist.
So there are a few ideas to play around with. For more buildings, search for ‘architectural rings’.
It Don’t Mean a Thing if it Ain’t Got That Bling
If you like this kind of post, you’ll also want to see these:
Armillary Rings: Handy for astronomers, astrologers, and navigators.
Compartment Rings: Hide your true allegiance, or carry a secret message.
Poison Rings: An old classic.
Gun Rings: Add more punch to your punch.
Eye Rings: Protection, divination, gaze weapons, and more.
Miscellany: No theme, but lots of possibilities.
Let us Bling: A Ring for Clerics that unfolds into a portable shrine.
Graeme Davis 
I like these! Im going to use the first ring in my upcoming Power behind the Throne campaign. But, apart from boosting the noble’s skills, dwarves have engineered this as a key to a special vault too. Thanks for this!
Such rings could give the wearer a mental map of the building they replicate and/or knowledge of what going on in them. Such rings might be able to guide the wearer to the place the replicate, or even teleport them there.