Los Angeles County, CA
With more than 10 million residents, Los Angeles County is home to more citizens than any other county in the nation. It's located in Southern California and was established Feburary 18, 1850. Aside from the massive population, it's also one of the nation's largest counties - encompassinig 4048 square miles. The county has 70 miles of coastline and is known for its temperate climate.