Recently, the Caverns Of Sonora in Texas was vandalized. This show cave is a National Natural Landmark and is considered by many to be one of the most beautiful caves in the world. It's most known for the world-famous Butterfly Formation. But now, the Butterfly Formation has been damaged. Maybe irreversibly.
Read a news article about the vandalism (complete with before and after pictures) here.
If you are someone who enjoys visiting "show caves" and you believe that all caves should be protected from damage, read this to offer some help.