San Francisco is a center of many architecturally striking sights. This section concentrates on a few highlights.

The Union Square and Financial District areas have a number of buildings worth checking out. One is the former Circle Gallery, 140 Maiden Lane. Now a gallery housing Folk Art International, Xanadu Tribal Arts, and Boretti Amber & Design, it's the only building in the city designed by Frank Lloyd Wright (in 1948). The gallery was the prototype for the Guggenheim's seashell-shaped circular gallery space, even though it was meant to serve as a retail space for V. C. Morris, a purveyor of glass and crystal. Note the arresting exterior, a solid wall with a circular entryway to the left. Maiden Lane is just off Union Square between Geary and Post streets.

The Hallidie Building, 130-150 Sutter St., designed by Willis Polk in 1917, is an ideal example of a glass-curtain building. The vast glass facade is miraculously suspended between the two cast-iron cornices. The fire escapes that course down each side of the building complete the proscenium-like theatrical effect.

Two prominent pieces of San Francisco's skyline are in the Financial District. The Transamerica Pyramid, 600 Montgomery St., between Clay and Washington streets, is one of the tallest structures in San Francisco. This corporate headquarters was completed in 1972, stands 48 stories tall, and is capped by a 212-foot spire. The former Bank of America World Headquarters, 555 California St., was designed by Wurster, Bernardi, and Emmons with Skidmore, Owings, and Merrill. This carnelian-marble-covered building dates from 1969 and is 52 stories tall. The focal point of the building's formal plaza is an abstract black granite sculpture, known locally as the "Banker's Heart," designed by Japanese architect Masayuki Nagare.

The Medical Dental Building, 450 Sutter St., is a steel-frame structure beautifully clad in terra cotta. It was designed by Miller and Pflueger in 1929. The entrance and the window frames are elaborately ornamented with Mayan relief work; the lobby ceiling is similarly decorated with gilding. Note the ornate elevators.

At the foot of Market Street you will find the Ferry Building. Built between 1895 and 1903, it served as the city's major transportation hub before the Golden Gate and Bay bridges were built; some 170 ferries docked here daily unloading Bay Area commuters until the 1930s. The tower that soars above the building was inspired by the Campanile of Venice and the Cathedral Tower in Seville. In 2003, a 4-year renovation was completed and the building is now a spectacular mixed-use landmark building featuring a 660-foot-long, skylit nave, which had been partially filled in and destroyed in the 1950s. If you stop by the Ferry Building, you might also want to go to Rincon Center, 99 Mission St., to see the WPA (Works Progress Administration) murals painted by the Russian artist Refregier in the post office.

Several important buildings are on or near Nob Hill. The Flood Mansion, 2222 Broadway St., at Webster Street, was built between 1885 and 1886 for James Clair Flood. Thanks to the Comstock Lode, Flood rose from being a bartender to one of the city's wealthiest men. He established the Nevada bank that later merged with Wells Fargo. The house cost $1.5 million to build at the time; the fence alone cost $30,000. It was designed by Augustus Laver and modified by Willis Polk after the 1906 earthquake to accommodate the Pacific Union Club. Unfortunately, you can't go inside: The building is now a private school.

Built by George Applegarth in 1913 for sugar magnate Adolph Spreckels, the Spreckels Mansion, 2080 Washington St., is currently home to romance novelist Danielle Steel (don't even try to get in to see her!). The extraordinary building has rounded-arch French doors on the first and second floors and curved balconies on the second floor. Inside, the original house featured an indoor pool in the basement, Adamesque fireplaces, and a circular Pompeian room with a fountain.

Finally, one of San Francisco's most ingenious architectural accomplishments is the San Francisco-Oakland Bay Bridge. Although it's visually less appealing than the nearby Golden Gate Bridge (except at night when it's lit up), the Bay Bridge is in many ways more spectacular. The silvery giant that links San Francisco with Oakland is one of the world's longest steel bridges (8 1/4 miles). It opened in 1936, 6 months before the Golden Gate. Each of its two decks contains five automobile lanes. The Bay Bridge is not a single bridge at all, but a superbly dovetailed series of spans joined midbay, at Yerba Buena Island, by one of the world's largest (in diameter) tunnels. To the west of Yerba Buena, the bridge is actually two separate suspension bridges, joined at a central anchorage. East of the island is a 1,400-foot cantilever span, followed by a succession of truss bridges. This east span of the bridge is finally being replaced after being damaged in the 1989 Loma Prieta earthquake and a years-long fight between city residents, planners, and designers. And it looks even more complex than it sounds. You can drive across the bridge (the toll is $4, paid westbound), or you can catch a bus at the Transbay Terminal (Mission St. at First St.) and ride to downtown Oakland.

Must-Sees for Architecture Buffs

Alamo Square Historic District -- San Francisco's collection of Victorian houses, known as Painted Ladies, is one of the city's most famous assets. Most of the 14,000 extant structures date from the second half of the 19th century and are private residences. Spread throughout the city, many have been beautifully restored and ornately painted. The small area bordered by Divisadero Street on the west, Golden Gate Avenue on the north, Webster Street on the east, and Fell Street on the south -- about 10 blocks west of the Civic Center -- has one of the city's greatest concentrations of Painted Ladies. One of the most famous views of San Francisco -- seen on postcards and posters all around the city -- depicts sharp-edged Financial District skyscrapers behind a row of Victorians. This fantastic juxtaposition can be seen from Alamo Square, in the center of the historic district, at Fulton and Steiner streets.

City Hall & Civic Center -- Built between 1913 and 1915, City Hall, located in the Civic Center District, is part of this "City Beautiful" complex done in the Beaux Arts style. The dome rises to a height of 306 feet on the exterior and is ornamented with oculi and topped by a lantern. The interior rotunda soars 112 feet and is finished in oak, marble, and limestone, with a monumental marble staircase leading to the second floor. With a major renovation completed in the late 1990s, the building was returned to its former splendor. No doubt you saw it on TV during early 2004, when much of the hoopla surrounding the gay marriage proceedings was depicted on the front steps. (Remember Rosie O'Donnell emerging from this very building after getting married to her girlfriend?) Public tours are given Monday through Friday at 10am, noon, and 2pm. Call tel. 415/554-4933 for details.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.