Union Square is downtown San Francisco's classic meeting plaza, where flagship stores, cable car turnarounds, and the Theater District converge around the Dewey Monument. The square covers about 1.05 ha (2.6 acres), was set aside for public use in 1850 AD, and took its name from pro-Union rallies before the Civil War.
If you want a structured first look after dark, start with a guided ghost walking tour around Union Square and nearby Chinatown, because it bundles local stories into one easy 90-minute route.