The term "Presidio" refers to a fortified military post established by the Spanish in the Americas. These installations were designed to protect settlers and missions from potential threats, such as attacks by indigenous groups or rival colonial powers. The most famous example is the Presidio of San Francisco, which was established in 1776 and later became a key military base for the United States. Today, many former presidios have been transformed into parks or historical sites. The Presidio of San Francisco is now part of the Golden Gate National Recreation Area, offering visitors scenic views, hiking trails, and historical exhibits that highlight its rich history.