La Brea Tar Pits, an area in Hancock Park, Los Angeles, where there is a natural accumulation of sticky asphalt derived from an ancient petroleum seep. The asphalt contains the bones of thousands of Ice Age animals that became trapped in it. Excavations begun in 1906 have yielded bones of saber-toothed tigers, big wolves, mastodons, giant ground sloths, bisons, camels, elephants, and lions. At an observation pit visitors can see some remaining fossils. The Los Angeles County Museum of Art covers part of the tar pits. Specimens from the pits are in the George C. Page La Brea Discoveries Museum in the park.