The Islamic State jihadist group has destroyed part of what's considered the most important temple at the ancient Syrian site of Palmyra. The 2,000-year-old Temple of Bel appears to have partly survived the attempt to demolish it with explosives. The reports come a week after IS blew up another temple at the ancient city. And, it has antiquarians throughout the world worried about further destruction of the Unesco World Heritage site. Geoff Steven is the chief executive of Our Place World Heritage. He's photographed and documented many World Heritage Sites throughout the world. And, he's just partnered up with the ultra-luxury small ship cruise line, Seabourn, to photograph some of the planet's most significant locations.