Brainstorming, dungeon creation ideas

[Phneri]

So, I'm putting together some ideas for this and thought I'd crowdsource:

Say you're a reasonably high-level mystic theurge (CL 16 or 17). Your adventuring party has largely disbanded, and being the knower of all things you've been entrusted with a number of powerful (and potentially very dangerous) artifacts.

Time passes and your grow older. In your twilight years you come to two realizations:

1. You will have no heirs
2. You will need to find a way to protect these artifacts.

How do you go about it?

[MagiMaster]

I don't remember how mystic theurge works, but you might could throw them into a dead magic demiplane with no portals.

[Joegoat]

Take on an apprentice, doesn't that sound like the becoming to someones great story?

[Goth Guru]

I don't know how much of this is copywritten, but the outlands, at the center, in the shadow of the spire with Sigil on top, even 9th level spells fail. Good place to build a vault holding really bad stuff. :)