The fall of the Syrian town of Tadmur, adjacent to the ruins of ancient Palmyra, to the Islamic State, has drawn much attention because of concern about the UNESCO World Heritage Site, in light of ISIS' destruction of antiquities in and around Mosul. The spectacular Roman-era ruins have been in danger in earlier rounds of fighting in the Syrian civil war, but the threat there was collateral damage, not deliberate destruction.
Appalling as the threat to Palmyra is, some perspective is in order Tadmur is not a major town, except as a tourist site, though there are military bases nearby; it is not a major prize like Raqqa or Deir al-Zor, but the fame of the ruins and the recent fall of (the far more important) Ramadi in Iraq combine to create a sense of alarm in the media. I keep hearing that ISIS "now controls 50% of Syria." But it controls a lot of desert and few real population centers, and Tadmur doesn't change that.