Union Square/Fisherman's Wharf
San Francisco’s manually operated cable car system is the last of its kind in the entire world (and, humble brag, the country’s only mobile historical landmark), which in and of itself makes it super cool. Sure, most of the riders are tourists (it costs $7 for a single ride), but when you’re hanging off of the side with the wind in your hair taking in the Bay views while flying down Taylor St you’ll get why everyone who’s visiting SF always looks so happy.
Golden Gate Park
The Academy of Sciences is one of the largest natural history museums in the world and is full of interesting things to see. Check out the Steinhart Aquarium, which is home to nearly 40,000 animals (including an albino alligator) or walk through an indoor rain forest with birds, butterflies, and reptiles. The Cal Academy also boasts a 75ft planetarium, and, of course, the spotlight-stealing penguins in the African Hall. At $35, it’s pricey and is definitely over-crowded on the weekends, but SF residents can get in for free on certain days. Not local to SF? No worries -- there’s also an adults-only NightLife party on Thursdays where tickets are just $15 (plus, there’s booze).