The entire Baja California peninsula is divided into two states, the northern simply called Baja California. The southern portion is Baja California Sur (south). The northern portion of Baja California became the 29th state in 1952, and it's capital is Mexicali, situated right next to the US border. When people think of Baja California, the border city of Tijuana probably comes to mind, but there are several nice resort areas as well, including Rosarito, Ensenada, and San Felipe.
All of the Baja region is home to very diverse geographical areas. There are beautiful deserts, semi-tropical areas, mountainous regions, and even pine forests. And because of it's location, there are still miles of undeveloped coastline. And because of this, and its proximity to the southwest United States, it has become a popular get away for many people.