For our May cover story we went straight to the experts to bring you the ultimate guide to 20 national parks. Here, preview three, then find out about some lesser-known wild lands vying for national park status and vote for your favorite.

Ten years ago, caver Chris Nicola began his investigation into a little-known tale of Holocaust survival. What he uncovered involved 38 Jews, one of the longest caves on Earth, and 344 days without daylight. Read the Q&A >>

Grab a ferry schedule and tune up your bike for the outdoor hedonist's ultimate mountain biking tour—island-hopping Alaska's Inside Passage. Enter the gallery >>