Alvarez has descended Mexico's Pit of the Swallows, navigated dangerous underground rivers in Papua New Guinea, and slogged through Central American caves. While rappelling in the sun-drenched Arabian Desert, Alvarez encountered one of the largest cave chambers in the world, and his search for the bones of early man in Pacific Grottos transported him to the origins of human history.

Chronicling high adventure and exploration, Alvarez's lecture will deliver the stunning views he has captured beneath the earth's surface. He will speak about our shared compulsion to explore, and how his search for adventure has led him to greater cultural awareness.

Alvarez has been a National Geographic photographer since 1995. His images have won awards in POYi, Communication Arts, and have been exhibited at Visa pour l'Image in Perpignan, France. Recent appearances include NPR, PBS and CBS News Sunday Morning.

Stephen lives with his family in Sewanee, Tennessee.