The PCs are going to be exploring a very roughly typical-fantasy-tech-level city whose inhabitents mysteriously disappeared (along with all the other sapient/sentient inhabitents of their planet) about 900-1200 years ago. There are no obvious signs of conflict or disaster (i.e. whatever befell them was a quick but not destructive), akin to the point you could nearly have walked in just after the disaster and the table set for dinner, so to speak.

The city's location is a high desert (e.g. Colorado plateau, to use an example I found on wiki when researching), on the top and bottom of a section of a deep river valley (like a much smaller version of the Grand Canyon).

What, given the age, climate and lack of later looting, plant-growth and much in the way of animal life, sort of accoutrements would we expect to have survived? Would wooden objects still be there? Would other organics be essentially freeze-dried? Would there still be books or tapestries, or would it mostly by now be dust-filled empty rooms with only a few more imperishable metal decorations left?