Visit a place like Mt. Rushmore or the Giza Pyramids, and it’s hard to imagine it disappearing. But World Heritage Sites are being damaged or lost at a steady pace--whether it’s the 1,000-year-old mosque destroyed in the recent Syrian conflict or the pyramid in Belize bulldozed this year to make road gravel.

"We're losing our heritage sites ... faster than we, the human race, can physically conserve them,” said Ben Kacyra, who founded the nonprofit CyArk, short for Cyber Archive. The group's goal is to digitally preserve World Heritage sites using 3-D laser scanning technology, starting with the 500 most at-risk places....