Decades after nearly going extinct, the world’s only existing population of Asiatic lions is overrunning a small reserve in western India. Now what?

For more than a decade, a team of intrepid researchers have been exploring the river systems of southern Africa, one paddle stroke at a time. Here’s how the work led to the discovery of a lifetime.

For centuries, the vanished Inca fortress of Ancocagua existed only in lore. Now, at a mountaintop site in Peru, researchers are zeroing in on a discovery that could reshape what we know of the empire’s last days.