Every Saturday, Bay Area residents get free admission to both the de Young Museum in Golden Gate Park and the Legion of Honor in Lincoln Park. Both are part of the Fine Arts Museums of San Francisco; bring proof of Bay Area residency (a driver's license or state ID with a Bay Area address works). Hours at both run 9:30am–5:15pm, with last entry at 5pm. The de Young is a short walk from the Ninth Avenue park entrance; the Legion sits out near Land's End with parking on the lot off 34th Avenue — use that lot, not the street, especially on foggy mornings when the turnaround fills fast. No BART-direct option to either, but the 44 O'Shaughnessy and 5 Fulton serve the de Young; the 18 46th Avenue gets you within a few blocks of the Legion.

The two museums aren't the same day trip. The de Young holds the Fine Arts Museums' American and international collections plus rotating contemporary shows — check the website before you go because ticketed special exhibitions sit behind a separate paywall even on free days. The Legion runs stronger on European paintings and the Rodin sculpture garden outside, which is free to walk regardless. Both have cafes; the de Young's Café de Young is the better lunch stop if you're spending the morning in the park.

If you have two hours, pick one and commit. The de Young's permanent collection on the second floor — American art through the 20th century — can be done well in 90 minutes if you skip the decorative arts wing. Save the Legion for a separate trip when the weather clears enough to make the garden worth it.