This lake of primal sludge, surrounded by a brash young city, is the most incongruous museum in Los Angeles, if not the country. The primeval  pools lured nearly 400 species of thirsty mammals, birds, amphibians and fish that last roamed Earth as much as 50,000 years ago, only to trap them in asphalt seeping up from underground oil deposits. One of the world’s richest excavation sites for Ice Age fossils, it has been coughing up saber-tooth cats, mastodons, camels, giant jaguars and dire wolves ever since scientists began extracting their remains in 1906. You can see the best of these next door at the Page Museum at the La Brea Tar Pits, boasting the world’s largest and most diverse collection of Ice Age plant and animal skeletons. The Fossil Lab lets you watch scientists and hordes of volunteers work on an estimated 100,000 cleaned but uncatalogued specimens and another million or so that remain to be scrubbed.The Observation Pit, which opened in 1952 and closed in the mid-’90s, reopened in summer 2014 to allow visitors to watch extractions in progress as a stop on the new Excavator Tour (timed tickets required). A 3-D movie is available for an extra charge, but it's not integral to your enjoyment.

-Christine Delsol