Pompeii, the ancient city destroyed in 79 A.D., is an archaeological treasure that has attracted millions of visitors from around the world. The city, going about its day, was buried and then preserved by the very ashes that eradicated it. The Grand Palais now offers virtual tours through the ruins and then reconstructs the space in immersive 3-D detail (the tool is in French, but the features are amazing). You can step back into that fateful day, back into the bustling Pompeii streets just before Mount Vesuvius erupted and disappeared everything within ten miles. —E.C.