Show your kids where Ice Age fossils come from by taking them to the stickiest park in town. The area formed when deposits of oil rose to the earth's surface, collected in shallow pools, and coagulated into asphalt. In the early 20th century geologists discovered that all that goo contained the largest collection of Pleistocene (Ice Age) fossils ever found at one location: more than 600 species of birds, mammals, plants, reptiles, and insects. Roughly 100 tons of fossil bones have been removed in excavations during the last 100 years, making this one of the world's most famous fossil sites. You can see most of the pits through chain-link fences, and the new Excavator Tour gets you as close as possible to the action.
Pit 91 and Project 23 are ongoing excavation projects; tours are offered, and you can volunteer to help with the excavations in the summer. Several pits are scattered around Hancock Park and the surrounding neighborhood; construction in the area has often had to accommodate them, and in nearby streets and along sidewalks, little bits of tar occasionally ooze up. The museum displays fossils from the tar pits and has a glass-walled laboratory that allows visitors to view paleontologists and volunteers as they work on specimens.