At 1,200 acres, Balboa Park is one of the largest urban cultural parks in the country — a genuine day’s worth of exploring packed with Spanish Colonial architecture, botanical gardens, walking paths, and nearly twenty museums covering everything from art to aerospace to natural history. It’s also home to the San Diego Zoo, so the two pair naturally into one outing if you have the stamina for it. Even without setting foot in a single museum, the park is worth the visit just for the Botanical Building, the reflecting pool, and the ornate Spreckels Organ Pavilion, which hosts free outdoor concerts on Sundays. Because it’s so large, it rewards a bit of planning — pick two or three museums rather than trying to see everything, and leave time to just wander the gardens. Free on the first Tuesday of most months for several museums, which is worth checking before you visit.