TLDR Up Front: When ISIS first captured Palmyra it marked the high-water mark of its expansion in Syria. Now - significantly reduced in territory, ISIS has once again been able to gain ground in the south. Though it is nowhere near as powerful as it once was.
InfoMullet: Another day, another archaeological treasure destroyed by ISIS, this time again in Palmyra.
TLDR Up Front: Volunteers on wikipedia's conflict sites work in anonymity to produce some of the most detailed, up to date and clearly labeled maps available on the conflicts in Syria and Iraq. You just have to trust wikipedia.