San Francisco is the financial, cultural, and transportational center of the San Francisco Bay Area, the technology capital of the world and a one of the prominent financial capitals of the United States. The San Francisco Bay Area also encompasses closely intertwined suburbs and cities which includes San Jose/ Silicon Valley, Berkeley and Oakland. The city of San Francisco exclusively encompasses a land area of about 46.9 square miles (121 km2) on the northern end of the San Francisco Peninsula, and is the second-most densely populated large city in the United States, after New York City. In 1776, Spanish colonists established a fort at the Golden Gate and a mission named for Saint Francis of Assisi ('Mission San Francisco de Asís') on the site. Upon independence from Spain in 1821, the area became part of Mexico but began to attract American migrants. Mexico officially ceded California to the United States at the end of the Mexican-American War in 1846. The California Gold Rush of 1849 transformed it into the largest city on the West Coast at the time. After three-quarters of the city was destroyed by the 1906 earthquake and fire, San Francisco was quickly rebuilt, and today San Francisco is renowned for its chilly summer fog, steep rolling hills, eclectic mix of Victorian and modern architecture, and its famous landmarks, including the Golden Gate Bridge, cable cars, and Chinatown. Across the Golden Gate Bridge in Marin County is the Muir Woods National Monument, home to a forest of ancient redwood trees.