Fremont is a city in Alameda County, California. It was incorporated on January 23, 1956, from the merger of five smaller communities: Centerville, Niles, Irvington, Mission San Jose, and Warm Springs. The city is named after John Charles Frémont, "the Great Pathfinder. " Fremont is located in the southeast section of the San Francisco Bay Area. Home to an estimated 213,000 people as of 2009,Fremont population will reach 249,300 in the year 2030. Fremont is now the fourth most populous city in the San Francisco Bay Area as the largest suburb in the metropolis. It is included as one of the towns in Silicon Valley. The area consisting of Fremont, Newark (an enclave of Fremont), and Union City was formerly known as Washington Township and is now known as the Tri-City Area. Fremont is the sister city to Elizabeth, South Australia (now part of the City of Playford); Puerto Peñasco, Mexico; Fukaya, Japan; Horta, Azores, Portugal; Lipa City, Philippines; and Jaipur, India.