I like the suggestion of the Dara Happan city trapped under the ice. They
could have been your standard Solar city following Yelm following his rules,
social structure, etc. And the ice started moving towards them. They were
fine until he died and then everything went to hell (pun intended). Faced
with this huge wall of ice heading towards them they turned to Lodril for
help. Through his magics they managed to keep their city intact. I can
picture the ice slowly moving up to the city and melting when it hit the
magic. Unfortunately the ice went up and over and around the city instead
leaving it trapped inside a huge dome. And there they're stuck. To an
outside Solar they practise a weird perversion of the natural order with
Lodril replacing Yelm and pretty much every Solar god is no longer
worshipped. What have they replaced them with?
As far as they know they're the only city in the entire world still
surviving with everything else buried under the ice.
Oliver