The Presidio of San Francisco, a wedge-shaped , 1480-acre national park, lies on the northern tip of the San Francisco Peninsula, at the base of the Golden Gate Bridge. For 218 years, the Presidio acted as a military fort for three countries-Spain, Mexico, and the United States. Today, the park is a National Historic Landmark District and home to commercial and residential establishments, recreational areas, and most famously, filmmaker George Lucas's digital arts enterprise. This last, particularly, will be of great interest to scholars and students of communication.

The Presidio began life in 1776, when the first Spanish settlement in San Francisco built its defensive garrison on the site. At the time it was a basic fort of adobe and wood, often damaged by earthquakes, and given very little support from Spanish authorities in Mexico. Forty-five years after the fort's creation, Mexico became independent and gained control of what was then the province of Alta California. Under Mexican sovereignty, the Presidio was even more isolated and unsupported, a situation that contributed to agitation in Alta California to secede from Mexico. That debate became moot, however, after the Mexican-American War of the 1840s in which the U.S. captured California.

The U.S. Army took possession of the Presidio in 1846. Initially an outpost for relations between the United States and Native Americans, the Presidio soon developed into the headquarters for the Sixth Army and the primary West Coat defense of the United States. It headquartered volunteer regiments in the Civil War; was the assembly point for Army forces of the Pacific in the Spanish-American War; the center of Federal aid and refugee shelter after the 1906 earthquake; and the Western Defense Command post during World War II. Renowned military figures William Tecumseh Sherman, Irvin McDowell, and John J. Pershing each served as commander of the fort. Of central importance was the Presidio's Letterman Army Hospital, a hub of casualty care for West-Coast installations and Pacific campaigns in every foreign military conflict of the 20th Century.

After the Vietnam War, the Army began gradually stepping down its presence at the Presidio; there were only a few units left by the time of the First Gulf War, when the garrison sent troops into action for the last time. Three years later, in 1994, the U.S. government deactivated the Sixth Army and transferred its home base, the Presidio, to the National Park Service. Today, the Service operates the park as part of the Golden Gate National Recreation Area. The Presidio Trust, a Congressionally chartered nonprofit organization, runs the "Main Post," the major section of the Presidio. Although many of the 800 garrison structures-including barracks, parade grounds, and the battery-still survive (and have been designated a National Historic Landmark District), the modern Presidio is generally characterized by many wooded areas, hills, and scenic vistas overlooking the Bay.

Because Congress has mandated both financial self-sufficiency for the park by 2013 and "preservation of the cultural and historic integrity of the Presidio for public use," the Presidio Trust has contracted commercial real estate management companies and developers to cultivate the area for residential and commercial tenancy. Currently, businesses located there include the Internet Archive (www.archive.org), The Gordon Moore Foundation, Tides Foundation, and The Bay School of San Francisco. By far the largest commercial resident of the park, however, is the LucasFilm enterprise.

George Lucas secured the development rights to a 15-acre section of the Presidio in June 1999. Over the next five years, Lucas invested $300 million into the construction of a campus that includes nearly 900,000 square feet of office space, a 2,500-car underground garage, and the state-of-the-art Letterman Digital Arts Center, built on the 23-acre site of the former Letterman Army Hospital (which was demolished in 2001). Letterman, which opened for business in 2005, is the new home of Industrial Light & Magic-arguably the world's premier visual effects studio for television and film-as well as the LucasArts video game developer and the marketing, online, and licensing arms of Lucasfilm Limited.

The buildings on the campus were designed by Gensler Architecture & Design and HKS, Inc. It is one of the "greenest" construction projects in the United States, designed to use 33% less energy and 30% less water than conventional buildings, as well as recycling much of the material that comprised the Letterman Hospital (including its 13-acre parking lot and much of its plumbing system). Unfortunately, these facilities are not currently open for public touring. However, 17 of the campus' 23 acres are designated as park space. Designed by award-winning landscape architect Lawrence Halprin (designer of Ghirardelli Square in San Francisco, and the FDR memorial in Washington), the grounds comprise hills and grass; hundreds of trees, plants, shrubs and flowers; walkways; and sitting areas. It also includes a creek and lagoon, and a number of fountains, the most prominent and popular of which is the "Yoda" fountain (featuring a statue of the Star Wars character) in the plaza of the Lucasfilm offices.

The Presidio Trust has made additional plans to build a promenade that will run from the park's Lombard Street gate, through the Main Post and Lucasfilm Campus, all the way to the Golden Gate Bridge.

Palace of Fine Arts

Another important sightseeing venue, the Palace of Fine Arts, is not inside the Presidio itself but just adjacent to it on the east, with the park and the Palace overlooking each other at most of their respective grounds. Built in Greco-Roman architectural style for the 1915 Panama-Pacific Exhibition, the palace that once displayed the impressionist works now houses the Exploratorium-a state-of-the-art science museum that is one of San Francisco's most popular tourist sites.

Founded by famed physicist Frank Oppenheimer, the Exploratorium's mission is an interactive one: to teach science through hands-on exhibits. It sits on the cutting-edge of scientific exhibitions by commissioning exhibits from visual and performing artists as well as scientists and educators, with such innovation that its exhibit designs are often duplicated for other science museums around the world. A popular feature of the Exploratorium is the Tactile Dome: a three-dimensional labyrinth, pitch-black and completely unlit. Visitors must make their way through the course using only their sense of touch.

For more information on the museum, check the Exploratorium's acclaimed and award-winning website (www.exploratorium.edu), which also features a number of online exhibits and experiments.

Transportation
The Presidio and the Exploratorium are accessible from the San Francisco Hilton via SF Muni bus. A $1.50 fare on Bus #45/Union-Stockton, from the corner of Stockton and Sutter Streets, will take you to Letterman Drive and Dewitt Road on the grounds of the Letterman Digital Arts Center. You can walk north across the campus to the Exploratorium. If you want to go deeper into the Presidio than the Letterman campus, transfer from there to the SF Muni Bus #29/Sunset, which goes to the old barracks in the center of the park.

To reach the Exploratorium from the hotel, take Bus #30/Stockton from the corner of Stockton and Stutter to the corner of Broderick and North Point, one block east of the grounds of the Palace of Fine Arts.