Every 14 days a language dies. By 2100, more than half of the more than 7,000 languages spoken on Earth—many of them never yet recorded—will likely disappear, taking with them a wealth of knowledge about history, culture, the natural environment, and how the human brain works.

National Geographic’s Enduring Voices Project (conducted in collaboration with the Living Tongues Institute for Endangered Languages) strives to preserve endangered languages by identifying language hotspots—the places on our planet with the most unique, poorly understood, or threatened indigenous languages—and documenting the languages and cultures within them.

A year ago Bulgarian, Romanian, and Irish were added to the list of official languages of the European Union, bringing the total to 23. That makes 506 language pairs, if anyone’s counting. A list of the languages can be found here.