San Francisco architecture combines practical, retrospective and modern influences into a functional, if surprising, hive of activity.
Some current trends are the bicycle-ization of the city with expanded bike lanes, ridership and political activity. In a similarly mobile manner, recession-born food carts are still the hottest thing in food culture and easily enjoyable at Off the Grid (or wherever they are). And via the efforts of the Burning Man organization and others, the quality and number of public art installations has been dramatically on the rise.
In terms of structural artifacts, the Golden Gate Bridge is probably the best known and most accessible. While nobody less than Frederick Law Olsted (designer of New York's Central Park) advised against the formation of Golden Gate Park on the assumption that trees wouldn't grow. The park is now (by far) the largest outdoor recreation area in the city and plays host to numerous and events.
Other notables are the Mission Dolores itself, the oldest still-standing building in SF, Grace Cathedral on Nob Hill, Coit Tower near North Beach, the Museum of Modern Art in SOMA, the Ferry Building along the Embarcadero, and a Chinatown rebuilt after the 1906 fire to look, rather than be, Chinese.
Other lesser-known standouts are the Xanadu Gallery by Union Square (Frank Lloyd Wright's prototype for the Guggenheim), the Cliff House at the north end of Ocean Beach (with a camera obscura on backside) and the Armory in the Mission.
On a residential scale, SF housing stock is long and skinny - 25 feet wide is a common width, and often split lengthwise - with lots of little rooms. A mansion by todays standards, the Haas-Lilienthal House is a well preserved/restored example, and open to the public. The "Painted Ladies" watching Alamo Square provide an iconic photo op, but are private residences.
SF City Guides volunteers lead a number of excellent architectural and related tours, providing deeper in-the-flesh exploration.
