Racetrack Playa: Home of Death Valley’s mysterious “sailing stones”

Racetrack Playa is a dry, shallow lake bed in California that is littered with hundreds of mysterious, moving stones. Also known as “sail stones,” these stones leave trails up to 1,500 feet long as they drift across the surface seemingly without reason.

The floating stones have puzzled researchers since the mid-20th century, but until 2013, no one had actually seen or recorded the stones' movement. However, it was clear that they regularly changed location, as they left grooves in the ground. Remarkably, some of the Racetrack Playa stones weigh around 320 kilograms.