Between the SM Sterling and John Gwynne books I have been reading lately, I want a world that the players would think is postapocalyptic, but the PCs don't, something like "grandpa is always going on about how every city guard used to have +3 swords, every other wizard could cast wish, and there were arcane gates all over the place, but I think he just has Old Timer's disease." The Eternal Empire of the Elves or Giants or whatever didn't collapse 1,000 years ago but more like 50 years ago.
Things are still raw. When the PC's want to go into the ruined city, the village elders don't oppose them because the elders are stodgy old foggies, but because some of them remember watching their parents or siblings being eaten by cannibals or dissolved by oozes in that same city.