Playboy Mansion: FOR SALE ... But Hef Gets to Stay

The Playboy Mansion -- the backdrop of some of the wildest parties ever thrown in L.A. -- is for sale ... TMZ has learned.

The 6 acre Holmby Hills estate, built in 1927, will be listed sometime within the next month. Our real estate sources say the owner -- Playboy Enterprises -- is looking to get somewhere north of $200 million.

Real estate sources with knowledge of the area say the owners are dreaming when it comes to price. They say the reality is ... the house is a tear-down and the real value is the acreage and that a comparable lot sold recently in the area for $60 mil, but the sources say because of its history the Mansion could go for anywhere between $80 mil and $90 mil.

Our sources say they believe the people at Playboy Enterprises will come back down to reality and list the estate at a realistic number.

There are several strings attached. We're told whoever buys it will be required to give Hugh Hefner a life estate, meaning he can continue to live in the mansion until he dies.

As for the other string ... we're told prospective buyers can tour the property but one area is off limits ... Hef's bedroom.