GO NOW: These Jaw Dropping Historic Sites May Soon be Gone

Imagine walking into a cave and finding perfectly preserved artwork drawn on the walls by cave people 173 centuries ago. It happened in 1940 when a young Frenchman discovered the Lascaux Caves in southwest France, and they soon became a major hit on the European tourist trail, billed as the “Sistine Chapel of Prehistory.” But in 1963, the caves were closed to the public for good. The reason? After little more than 20 years, visitors’ breath had changed the atmosphere in a way that promoted the growth of fungi, and the 173,000-year-old art had seriously corroded. Today, you can only visit a replica.

Turns out nothing really does last forever — even things that have previously stood the test of time. “Development, neglect, war, weather, and the very act of breathing” can seriously damage the world’s most magnificent creations, according to Benjamin Haley, communications manager at the World Monuments Fund (WMF), a nonprofit whose mission is to protect at-risk cultural sites. The legacies of some of history’s most creative and enigmatic civilizations might soon be casualties of the modern era.

The WMF has put hundreds of places on its Watch List since 1996 and is working to ensure that they are preserved. The UNESCO World Heritage danger list contains 46 sites that it is currently working to preserve. We’ve gathered five places you should visit right now — before they’re closed for tourism or disappear.