Some PD just scratches the surface. This national parks program takes teachers deep underground.

At Mammoth Cave National Park, a group of educators got a hands-on look at science, technology, engineering and mathematics (STEM) curricula this July as part of an overnight professional development workshop.

Teachers hiked through the historical Kentucky cave system while sifting through sediment for aquatic macroinvertebrates, exploring the intersections of social studies and science, and learning how to enhance their own lessons.

Produced, filmed, and edited by Sam Mallon for Education Week.