Pope Francis is resting Thursday after a peaceful night during his third week of hospital treatment for double pneumonia.

Built on land donated by Pope Pius XI to the theologian and physician Agostino Gemelli in 1934, it has become known as the "Pope's Hospital." John Paul II even nicknamed it "Vatican Three," with St Peter's Square being Vatican One, and the papal residence at Castel Gandolfo, Vatican Two.

Pope Francis has spent 18 full days at Rome's Gemelli hospital recovering from double pneumonia. It's by far the longest hospitalization of his 12-year papacy, and there is no indication how long it may still last.