It was shot in a body of water called Jellyfish Lake, which is home to millions of the alien-like animals.
The species seen here is the golden jellyfish, which are always on the move as the sun rises and sets to expose the light to their symbiotic algae.
According to National Geographic:
Before sunrise, the jellies cluster along the saltwater lake’s western shore. Each morning around 6, when dawn brightens the eastern sky, they begin to swim toward the light. Pumping water through their bells, these jellyfish use a type of jet propulsion to follow the sunlight until they nearly reach the eastern shore—stopping just short of the shadows caused by lakeside trees.
They also are pretty harmless, so swimmers don’t have to worry about getting stung by the numerous creatures. Because they’ve been isolated to this one spot, their sting has gradually gotten weaker to the point where you would hardly feel anything, according to The Nature Conservacy.
Anyone is allowed to snorkel around in the lake, you just can’t go scuba diving.
“Swimming with literally millions of jellyfish was absolutely surreal,” the uploader writes in the caption. “A reminder that there will always be surprises out there!”