California is a territory in the United States Pacific Region. With a total area of about 163,696 square miles (423,970 km2) with 39.6 million people, California is the most populated U.S. state and the third largest by region. The seat of the state is Sacramento. The Greater Los Angeles Area and the San Francisco Bay Area are the second and fifth most populated urban areas of the country, with 18.7 million people and 9.7 million respectively. Los Angeles is the most populous city in California, and the second most populous city in the country, after New York City. California also has the most populated county of the nation, Los Angeles County, and San Bernardino County, the largest county by population. San Francisco City and County is both the second-most densely populated metropolitan city in the country after New York City and the fifth-most densely populated county, behind only four of the five boroughs of New York City.
With a gross state product of $3.0 trillion, California's economy is greater than any other U.S. state and is the world's largest sub-national economy. If it were a nation, California would be the world's fifth largest economy (larger than the United Kingdom, France, or India), and by 2017 it would be the 36th most populous. The Greater Los Angeles Area and the San Francisco Bay Area are the second and third largest regional economies of the country ($1.29 trillion and $1.03 trillion respectively as of 2018), following the metropolitan area of New York. The PSA San Francisco Bay Area had the nation's highest per capita gross domestic product in 2018 ($106,757) for large primary statistical areas and is home to three of the world's ten largest market capitalization corporations and three of the world's ten richest people.
The government was a pioneer of roadbuilding. One of the most prominent landmarks of the region, the Golden Gate Bridge, was the world's longest main suspension bridge span between 1937 (when it opened) and 1964 at 4,200 feet (1,300 m). This highway bridge is a popular tourist attraction with its orange paint and panoramic views of the bay as well as accommodating pedestrians and bicyclists. The San Francisco–Oakland Bay Bridge (often the "Bay Bridge" abbreviated), opened in 1936, carries on two decks about 280,000 vehicles a day. The two sections meet at Yerba Buena Island at 76 feet (23 m) long by 58 feet (18 m) high through the world's largest diameter transportation bore tunnel. The Arroyo Seco Parkway, which connects Los Angeles and Pasadena, opened as the Western United States ' first freeway in 1940. It was later extended south to the downtown Los Angeles Four Level Interchange, considered to be the first ever constructed stack interchange.Read: California Wikipedia Page