This 30 bedroom mansion boasts its own bowling alley, roller skating rink and Olympic sized swimming pool to make it the largest family home ever built in the US. Time share mogul David Siegel and his former beauty queen wife Jacqueline began building the huge estate three years ago. But with almost 18 months of work still to be carried out on the property they have put it on the market at $75m. Experts believe a further $25m needs to be spent before anyone can move in.