For the next couple of weeks we will be checking out some homes in the most expensive zip codes in the United States, up today, 60611 . This zip code is in Chicago, Illinois and encompasses pricey Chicago's Gold Coast area. This zip code has a median price of $1,954,000 with an appreciation rate of 236% since 1990.

Right now, the most expensive listings in this area belong to the Chicago Spire, the massive spiraled Santiago Calatrava masterpiece that will be the new defining piece in the Chicago skyline. The MLS is also sprinkled with some pricey listings for Trump's Chicago offering. But for today's estate I chose something a little older that speaks to this area's history. This duplex is part of a building built in 1913, designed by architect Benjamin Marshall and located on East Lake Shore Drive. The unit was purchased as raw space by the current owners in 1998 and redesigned by architect Scott Himmel. The main level has a round entry foyer with curved stairway, large living room with lake views, a separate dining room/library, family room, eat-in kitchen with breakfast room and butler's pantry, and a separate laundry room. The upper level has three bedrooms including a master suite with a study, dressing rooms and a terrace over looking the lake. This home is listed at $5.6 million.

One of the unfair truths about the real estate market is that the most expensive neighborhoods are the ones that tend to rise the fastest when times are good -- and are also the ones that hold onto their value the best when times are bad.

So, even as prices plummet in places like Las Vegas and Orlando, FL, you will likely do better in the long run with your real estate dollar if you buy a home in an expensive neighborhood that is currently retaining its home price values.

To see just what you would pay for a home in one of America's most expensive neighborhood, Luxist asked NeighborhoodScout, a research firm with a huge database of neighborhood statistics, to provide a list of the most expensive neighborhoods around the country by zip code.

Dr. Andrew Schiller, a geographer and founder and president of NeighborhoodScout, did this research. His initial study found that many of the priciest zip codes are clustered within 30 miles of Los Angeles and Manhattan. "Around the biggest cities, there is a lot of demand and the greatest opportunities for people to make money," he explains. He notes these neighborhoods also tend to have great schools, wonderful views, nearby outdoor recreation and other amenities.

So as not to have our whole list made up of homes on either coast, we asked Schiller to include zip codes in all quadrants of the U.S. That explains why we include some of the most expensive zip codes in the Mid West, even though they are actually less expensive than quite a number of other zip codes found around the cities on either coast that we didn't include on our list. The result is a geographically diverse list of the 30 most expensive zip codes.

Luxist editor Deidre Woollard supplemented the research by identifying a property for sale and including it as the Estate of the Day.

If you are real estate shopping today and worried that prices could fall further across the country, buying in one of the most expensive zip codes in your region could be a smart strategy. "There is no doubt," says Schiller, "they do hold their value."