For the curious, educated lot you all are, none of these are probably new. But I thought I'd share anyway. Some resources for dungeon inscriptions:
Early Chinese Writing.
There's a cool example of how a Read Languages type of spell doesn't necessarily let you know what an inscription means in the page above. The sign that looks a bit like a dollar sign to me is for "steadfast." Imagine it inscribed on a tomb passage. Perhaps it means "be steadfast and you will prevail", perhaps it means "this passage is a steadfast defense and you are likely to die." *(whoops, it was "unyielding").
Also an example of how symbols change through time. You could pick some of these oldest symbols to use and I doubt anyone would even associate them with Chinese, they look so different.
Central American Hieroglyphic Writing, has fewer symbols. It does have the Mayan symbols for months and days though, which could be interesting if different tombs can only be accessed at certain time of year. Or that's when a ritual needs to be performed to be successful.
Cretan Pictographs and Prae-Phoenician Script are largely unknown, or were at the time of this book. So if you are the type to get hung up on accuracy just grab some of these and feel free to make them mean what you want. Another example from the same book:
The Hieroglyphics of Horapollo Nilous.
Now for the serendipity. Apparently that last book was supposedly written by an Egyptian priest to catalogue the meaning of some 189 hieroglyphs before they were lost to the ages. This text was translated into Greek by someone named Philippus much later. The book was then found on an island in the middle ages and became very popular. Except the whole thing is, not a hoax, but a misunderstanding of what hieroglyphs were, and feeding into what folks wanted them to be, mystical, religious symbols. So by 1543 you end up with this edition of the book, Orvs Apollo de Ægypte, with woodcuts for all the symbols that don't even depict the Egyptian hieroglyphs any more!
I'd like to do more with dungeon inscriptions, maybe a chart of who inscribed this kind of like the Why is the secret door secret one. But we'll see. My boss is on leave and so my work has been extra hard lately. I haven't even gamed in weeks. Feels good to just find and share those last weird pics for now.