03/18/2010 05:12 am ET Updated May 25, 2011

L.A.-Area Real Estate Agents Are Holding Open Mansions

For Florence Mattar, each open house has a routine. She drives around the neighborhood placing signs, brings in fresh flowers, stocks the refrigerator with bottled water and sets out a sign-in sheet.

Similar scenes play out across Southern California every weekend, with one expensive exception. The Tuscan-style house she is "sitting," to use the industry term, is listed at $21.9 million. And anyone is welcome to see it. All 9,691 square feet of it.