The historical significance and emotional impact of the chain of twenty-one Spanish Missions that stretch from San Diego to Sonoma is undeniable. Their beauty, stature and character underlie the formation of California and are part of our national heritage – the missions are cultural treasures. Over time, many mission enclaves have developed into some of California’s most significant cities: San Diego, Santa Barbara, San Luis Obispo, San Jose, San Francisco and Sonoma. All twenty-one missions are California Historical Landmarks and many have also been designated National Historic Landmarks. Established as a series of religious and military outposts by Franciscan missionaries to stem the tide of Russian colonization of America and secure Spain’s control of Alta California, the missions are among the most popular tourist destinations in California, attracting millions of visitors each year.