Solo, Natural History Museum of LA County works.
A broad classic natural-history museum in Exposition Park, strongest in two specific places: the Dinosaur Hall (a dramatic, light-filled gallery with a famous mounted T. rex growth series) and the dazzling Gem and Mineral vault. The under-rated move is to pair the indoor halls with the outdoor Nature Gardens — a 3.5-acre living exhibit with a pond and pollinator beds that turns a rainy-day backup into a genuinely pleasant half-day. It's not a marquee must-see, and parking and crowds spike around USC events next door, but for dinosaur-loving kids and the Gem vault it earns its couple of hours.