All the Sans and Santas are California Missions [1] along the El Camino Real [2], also know as US 101 for the most part:
[1] http://en.wikipedia.org/wiki/Spanish_missions_in_California [2] http://en.wikipedia.org/wiki/El_Camino_Real_(California)
[1] http://en.wikipedia.org/wiki/Spanish_missions_in_California [2] http://en.wikipedia.org/wiki/El_Camino_Real_(California)
Not all the Sans and Santas in California are missions; there are 21 missions -- not all of which are in cities named "San" or "Santa" (e.g., Mission San Francisco de Solano is in Sonoma, CA) -- and 33 cities that are "San" or "Santa"-something.