Under construction in the Principality of Monaco, the world's most expensive real estate market, is the Odeon tower. Started in 2009, the 49 storey, double tower skyscraper will be one of Europe's tallest residential buildings when completed. When finished in the second half of next year, the project is expected to have 70 luxury condominiums, including two sky duplexes boasting 13,000 square feet each, and an incredible 5 floor, 35,500 square foot penthouse. The penthouse will include it's own private rooftop swimming pool. Monaco is already famed for appealing to the ultra wealthy. With it's yacht-filled marinas, world-class hotels and casino, and home to the Formula One Grand Prix and Rolex Tennis Masters tournament, Monaco is a playground for some of the richest people in the world. The current record for most expensive condo is held by one sold in London's One Hyde Park, at $212 million. The price on this penthouse could easily surpass that, with estimates ranging from $250 million to over $300 million. Just imagine the payments!