The Holy Crib at the Vatican's Bascilica of Saint Mary Major

"In the crypt under the high altar lies the celebrated relic known as the Holy Crib. A statue of Pope Pius IX kneeling before the ancient wooden pieces of the manger serves as an example to the faithful who come to see the first humble crib of the Savior. Pius IX's devotion to the Holy Crib led him to commission the crypt chapel, and his coat of arms is visible above the altar" (Vatican description).

Go There Now!

(Well, almost.  Click for the Vatican's virtual tour of Santa Maria Maggiore.)