Walnut Creek is a city in Contra Costa County, California, United States, located in the East Bay region of the San Francisco Bay Area, about 16 miles (26 km) east of the city of Oakland. With a total estimated population of 70,166, Walnut Creek serves as a hub for its neighboring cities because of its location at the junction of the highways from Sacramento and San Jose (I-680) and San Francisco/Oakland (SR-24) and its accessibility by BART. Its active downtown neighborhood features hundred-year-old buildings and extensive high-end retail establishments.

Oakland is the largest city and the county seat of Alameda County, California. A major West Coast port city, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the San Francisco Bay Area, the eighth most populated city in California, and the 45th most populated city in the United States. With a population of 440,646 as of 2020, it serves as a trade center for the San Francisco Bay Area; the Port of Oakland is the busiest port in the San Francisco Bay, the entirety of Northern California, and the fifth busiest in the United States of America. An act to incorporate the city was passed on May 4, 1852, and incorporation was later approved on March 25, 1854. Oakland is a charter city.Oakland's territory covers what was once a mosaic of California coastal terrace prairie, oak woodland, and north coastal scrub. Its land served as a resource when its hillside oak and redwood timber were logged to build San Francisco. The fertile flatland soils helped it become a prolific agricultural region. In the late 1860s, Oakland was selected as the western terminal of the Transcontinental Railroad. Following the 1906 San Francisco earthquake, many San Francisco citizens moved to Oakland, enlarging the population, increasing its housing stock, and improving its infrastructure. It continued to grow in the 20th century with its busy port, shipyards, and a thriving automobile manufacturing industry.

Palo Alto (; Spanish for "tall stick") is a charter city located in the northwestern corner of Santa Clara County, California, United States, in the San Francisco Bay Area. The city is named after a coastal redwood tree known as El Palo Alto. The city was established by Leland Stanford Sr. when he founded Stanford University, following the death of his son, Leland Stanford Jr. Palo Alto includes portions of Stanford University and shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. As of the 2010 census, the city's total resident population is 64,403. Palo Alto is one of the most expensive cities in the United States in which to live and its residents are among the most educated in the country. As one of the principal cities of Silicon Valley, Palo Alto is headquarters to a number of high-technology companies, including Hewlett-Packard (HP), Space Systems/Loral, VMware, Tesla, Ford Research and Innovation Center, PARC, IDEO, Skype, Houzz, and Lockheed Martin Advanced Technology Center. Palo Alto has also served as an incubator and was headquarters to several other prominent high-technology companies including Apple, Google, Facebook, Logitech, Intuit, Pinterest, and PayPal.

Berkeley ( BURK-lee) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emeryville to the south and the city of Albany and the unincorporated community of Kensington to the north. Its eastern border with Contra Costa County generally follows the ridge of the Berkeley Hills. The 2020 census recorded a population of 124,321. Berkeley is home to the oldest campus in the University of California system, the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, which is managed and operated by the university. It also has the Graduate Theological Union, one of the largest religious studies institutions in the world. Berkeley is considered one of the most socially liberal cities in the United States.