Last year, Microsoft co-founder Paul Allen sold a glassy contemporary on Malibu’s billionaire-lined Carbon Beach for $28.8 million to Leslie Moonves because — so the scuttlebutt went — he didn’t care so much for the incessant pounding of the surf. His alleged aversion to the sound of crashing waves, however, hasn’t stopped the quirky multibillionaire from poking around for another beachfront bauble and, so snitches Our Fairy Godmother in Bel Air and Malibu real estate mover and shaker Heinrich Manoover, he recently kicked up the sand and subsequently backed out of the purchase of a Frank Gehry-designed mansion on Malibu’s Broad Beach. The idiosyncratically massed 11,000-plus square-foot residence, available off-market at $49.75 million, sits on almost 1.5 acres and offers six bedrooms, 10 bathrooms, a 60-foot lap pool and lighted tennis court. A sprawling ground-floor loggia with fireplace spills out to a wide lawn that rolls down to the unsightly rock revetment that Broad Beach homeowners installed several years ago at tremendous expense to keep the ocean from overtaking their multimillion-dollar homes.

Allen, worth close to $17.5 billion dollars, is a renowned real estate high roller, who presides over a property portfolio that might easily bankrupt a lesser billionaire. In addition to a yacht substantially longer than a football field, our research shows the philanthropic tycoon maintains a 13,000-square-foot Beverly Hills mansion where a funicular links the pool deck to the tennis court. There’s also a 22,000-square-foot mansion in Atherton, Calif., a multi-acre compound on Mercer Island near Seattle, a duplex penthouse atop one of New York’s most glorified Fifth Avenue co-ops, a townhouse on a cobblestone street in London’s Holland Park, and, lest we forget, his prominent hilltop villa in St-Jean-Cap-Ferrat on France’s Cote d’Azur.

listing photos: Pritchett-Rapf