One of the best places in the United States to find examples of Victorian architecture is San Francisco. The houses seem to fit well into the landscape of steep hills with houses crammed up against each other.
The Victorian style was architecture used during the reign of Queen Victoria in Great Britain (1837-1901). Victorian architecture originated in Europe as a combination of revivals of older styles (such as Gothic and Italianate). The architects tried to revive the old styles, and also incorporate modern needs and attitudes.
There are 3 distinct periods; Italianate, Eastlake (stick), and Queen Anne. San Francisco & the Bay Area had more so called Victorian architecture than any other area in the world.It also developed a style all it's own.
One reason Victorian architecture caught on here was the local building material: redwood. Because it's soft it's easy to carve by machine, all that fancy trim could be mass-produced.
Victorian style houses were often built narrow and tall. That way, they could easily be lined up side to side. They had steep roofs, decorations on the outside, and often multicolored walls. Some common characteristics of Victorian architecture are bay windows, stairs to the front door, and cone shaped turrets. It is also common to have horizontal ridges at the roof line and above each window.

Types of San Francisco Victorians

         There are three main styles of San Francisco Victorian architecture, although in later years there were many houses that had attributes from more than one style and sometimes all three.          
Queen Anne: The overall shape of the house is assymetrical, they have a steep gabled roof, shingled insets, slanted bay windows, and often have a turret or tower. Flourishes include lots of gingerbread, spindles, ornate cornices, brackets, and lead or stained glass windows.          
Stick/Eastlake: This style includes square bay windows which let in more light than slanted bays, flat roof lines and free-style decorations, turned, square, or round columns, false-fronts to make them look taller, and are reminiscent of the furniture of Charles Eastlake.          
Italianate: Italianate was influenced by the architecture of Renaissance Italy with flat roof lines, corniced eaves, angled bay windows and Corinthian columned porches. Their interior design had heavily molded, yet graceful door frames and wainscoting that complemented the contemporary Victorian furniture styles.          
Other styles represented in San Francisco, in smaller numbers, are Greek Revival, Gothic and Tudor.