La Brea Tar Pits and Museum

This guide to the La Brea Tar Pits and Museum in Los Angeles opens in 2006, when a bulldozer clearing ground for a parking garage struck a nearly whole Columbian mammoth skeleton, thirty-seven thousand years old, that scientists came to call Zed. It explains how the asphalt seeps here work as what researchers call a predator trap, pulling in bison and drawing wolves that then get stuck chasing an easy meal. The guide turns to what a study of Zed's own bones revealed about his final days, asking what brought a giant like him into that ground.