The stone store museum, which we see today, was the result of a raid by border bandits in 1875. The raid left the store owners so shaken up that they decided to re-build their store into a stone "fortress" of sorts to ensure protection from any future issues.
Beyond a store, the Stone Store Museum also once served as a post office, bank and headquarters for social gatherings within the community. The store served people on both sides of the border at the time and was also the last home to the Buffalo Soldiers!
Personal Experience: We stopped by the museum one day after camping out at Coyote's UFO Repair Shop in Jacumba the night before. I know there are a lot of fun, hidden gems out in Campo but I am yet to explore them. This museum was really cool and has a rich history. I would recommend it if you're in the area but probably would not venture too far if this is the only thing you have planned for the day.
Right down the road we found an old kiln. Wonder what it was used for!