Investing in San Francisco real estate is one of the most exclusive real estate ventures one could undertake. The reason for this is that the value of homes in San Francisco is significantly more than the vast majority of the United States. As with any other equity, location and scarcity contribute to the high costs of real estate. The Great Fire of San Francisco during the early 20th century destroyed much of the city. Additionally, destructive earthquakes during other parts of the 20th century destroyed much property as well. As such, future developments centered on apartment complexes making the number of homes much smaller in scope. This drove the property values of homes up significantly over time. This is not to say that there are no opportunities for purchasing affordable real estate in the San Francisco area. The city has not been immune to the recent sub-prime mortgage crisis. There have been a number of foreclosures of property in San Francisco and this, in turn, has opened the door for a number of foreclosure auctions where property might be acquired more reasonably. Perhaps, in time, these purchases might turn out to be huge equity gains on the resale market.