Villa Leopolda in Villefranche-sur-Mer

VILLEFRANCE-SUR-MER, FRANCE – DECEMBER 4, 1999: General view taken on December 4, 1999 of Villa Leopolda in Villefranche-sur-Mer, France. The villa, which was built by King Leopold II of Belgium in 1902, was recently sold for 500 million euros, making it the most expensive private residence in the world. (Photo by AFP PHOTO/ VANINA LUCCHESI/Getty Images)