Border Field State Park is the southermost point in California, adjacent to Tijuana. The US-Mexican border survey which took place following the Treaty of Guadalupe Hidalgo which ended the Mexican-American war in 1848, began at Border Field.
A US citizen convicted of smuggling “43 pounds of heroin, 47 pounds of methamphetamine and 43 pounds of cocaine” got married there to a woman from Mexico despite being cleared by a border patrol background check.