In a short, special one-off episode of "One Thing to do in L.A. this Week," we take you to the site of what the L.A. Times called The Most Important Event in California History: Campo de Cahuenga, directly across the street from Universal Studios, which marks the spot that ended the fighting of the Mexican-American War! This is the spot that enabled California to become part of the United States, and it's right in our backyard. THIS is what you're going to do in L.A. this week.