Mission Dolores (3321 16th St., 415/621-8203, www.missiondolores.org [1], daily May–Oct. 9 a.m.–4:30 p.m., Nov.–Apr. 9 a.m.–4 p.m.), formally named Mission San Francisco des Asis, was founded in 1776. Today, the Mission is the oldest intact building in the City [2], survivor of the 1906 earthquake and fire, the 1989 Loma Prieta quake, and more than 200 years of use.
You can attend Catholic services here each Sunday. Or you can visit the Old Mission Museum and the Basilica, which houses artifacts from the Native Americans and Spanish of the 18th century.
The beauty and grandeur of the Mission recall the heyday of the Spanish empire in California, so important to the history of the state as it is today.
Links:
[1] http://www.missiondolores.org
[2] http://www.moon.com/destinations/california/san-francisco-and-the-bay-area