Cal Academy is an aquarium, planetarium, rainforest, and natural history museum wrapped into one. Though it’s considered California’s oldest museum—originally established in 1853—it has morphed over time to remain a vital, vibrant space. In all, the 400,000-square-foot building contains over 26 million specimens. The Kimball Natural History Museum is perhaps best known for the Africa Hall, where taxidermied animals are displayed behind glass, while the Project Lab showcases real scientists doing research in public view. The Morrison Planetarium features the world’s largest completely digital planetarium dome, measuring 90 feet in diameter. You can meander among the butterflies, marine life, and birds of the rainforest within a humid, 90-foot glass dome. And the impressive Steinhart Aquarium includes exhibits of coral reef, tidepool, and swamp habitats, as well as a colony of African penguins. The museum also has one of the most striking rooftops in the city, covered in seven rolling hills and home to an estimated 1.7 million plants.