The adobe walls of this 1791 church are a reminder of the Latin American origins of San Francisco, and the cool, dark interior is a fascinating glimpse into the minds of its settlers. There are a few simple pews in front of a plain wooden altar and small plaques marking the burial sites of important figures, as well as a diorama showing how the mission looked originally. Don't miss the cemetery, it's a haunting little place filled with rambling rose bushes. Entry is free with a $5 recommended donation.