Like the Vatican which it protects, the Knights of Malta are one of three sovreign nations in the City of Rome. Their nation is about a 2 hectare (5 acre) bit of land atop one of the original seven hills of the Eternal City. Originally the Knights Templar, after their successful siege of King Solomon's Temple in Jerusalem in the 12th century, the order became the first global bankers. Centuries later, the order has transitioned to charitable healthcare work, but outside of the public eye. In fact, this garden -- world headquarters, as it were -- is visible only from through the keyhole at the front gate!