Founded by the Jesuits in the late 18th century, San Juan Bautista is home to one of the many missions along the California coast. It's located about 30 miles south of San Jose, between there and Monterey. (To get there, one would take US-101 south to CA-156, the road leading to San Juan Bautista and Hollister.)
My grandfather and uncle both had farms just outside of there, so this was more of a family stop than anything. This was the first time my wife had been there, though, so I showed her some of the highlights of the town.
Our first stop was the cemetery. It's located on a hill overlooking the northern side of the town, and has the graves of many of the prominent names of California history (the Breens, one of the surviving families of the Donner Party tragedy). My uncle and grandfather are buried there, so it was definitely a personal stop for me.
The next stop was the mission. It's largely intact (despite the fact that it's sitting right on top of the San Andreas Fault), and is still being used as a church today. We were there on Sunday, and mass was just letting out. Of course, on Sunday, many of the historical aspects of the mission are closed (visitor center, gift shop, and so on), but the walking tour is still available.
And San Juan is full of little shops along Main Street. I highly recommend the bakery - they make excellent pastries and french bread. It was hot out of the oven when we got there, and - well, we just couldn't resist. ;-)