PHOTOS: Old Money And Tech Money Go Head-To-Head On San Francisco's Billionaire's Row

When the 1906 San Francisco earthquake and fire wiped the city's slate clean, the wealthy stood around the burned rubble of their Nob Hill homes and took a cool, hard look at San Francisco Bay.

The best view in the city was in Pacific Heights, and with that swathe of real estate now up for grabs the big money built there and settled in.

Through the Great Depression and both World Wars, the residents of Pacific Heights built mansions in an ex-frontier town that now sell for nearly $3,280 per square foot.

Today's buyers, however, have given this slice of San Francisco the name "Billionaire's Row." And those billionaires include a lot of tech names mingling with San Fran's "Old Money" crowd.