Sticky, obsidian-coloured and filled with trash, how could there be anything to see in these opaque tar pits? They look more like a swamp slowly taking over metropolitan LA than anything else. However, its inky depths are actually one of the world’s most valuable time capsules, and conceal many hidden secrets from as far back as prehistoric times. The natural asphalt has been seeping up from the ground for over tens of thousands of years, slowly preserving the bones of animals trapped within the gooey liquid. Since scientists first found this archaeological gold mine, over 3.5 million fossils that date back from the Ice Age have been discovered, with specimens of mammoths, mollusks and mountain lions among others. And it’s still yielding up its secrets, albeit reluctantly—paleontologists still dig there 361 days a year, painstakingly excavating the bones from the tar pits. Amusingly, many visitors do not realize that the tar pits are still a place of active scientific research, often mistaking the excavators for actors, or part of an art exhibit, or even robots. If you would like to see fascinating discoveries being made right in front of your eyes, you have to go to the La Brea Tar Pits. Just don’t get too sucked in.