On our way to Alberobello, we made a stop at the Reggia di Caserta (Palazzo Reale). It's a pectacular 18th century Baroque palace known as the "Italian Versailles" and just as you would expect... IT'S HUGE.  In fact, it's the largest royal residence in the world with over 2 million m³ and covers an area of about 47,000 m² (according to Wikipedia). It's also (more importantly) the setting for Queen Amidala's royal palace on Naboo in the 1999 film Star Wars Episode I: The Phantom Menace.