Even on a tight schedule, Golden Gate Park earns the hours.
Allow Half day.
Free, vast, and gloriously low-pressure: rent a bike, find the Japanese Tea Garden or the bison paddock, and you've got a whole restorative day with zero queue.
Golden Gate Park spans 1,017 acres, making it larger than New York's Central Park, and has kept a bison herd in a public paddock since the 1890s · en.wikipedia.org