PALMYRA WATCH: Activists: Syrian Pro-Government Forces Near IS-Held Palmyra (AP). Great. ISIS vs. the Syrian Government and Hezbollah. That's not much of a choice, but the latter will at least take care of what's left of the ruins on the site if they recapture it.
Background on Palmyra, its history, the ancient Aramaic dialect spoken there (Palmyrene), and the city's tragic recent fate, now a second time, in the hands of ISIS is here with many, many links.