"The Adoration of the Mystic Lamb" by Hubert and Jan Van Eyck
Erich Lessing/Art Resource, N.Y.

Want to learn more? Here are other works looted by Nazis and returned by the Monuments Men:

Visit the Jeu de Paume museum, where the valiant Rose Valland risked her life every day to keep a catalog of the art being plundered by the Nazis. At the Louvre, see one of Vermeer’s most cherished works, “The Astronomer.” It was owned by Edouard de Rothschild before it was confiscated by the Nazis, and it was donated to the Louvre after it was returned by the Monuments Men.

At the Church of Our Lady in Bruges, see Michelangelo’s “Madonna of Bruges,” a luminous white-marble sculpture of an extraordinarily beautiful Virgin Mary with the infant Jesus. Carried off by the Nazis in 1944, it was found in an Austrian salt mine by the Monuments Men and returned.

In St. Bavo’s Cathedral is “The Adoration of the Mystic Lamb,” completed during the 15th century by the Van Eyck brothers, Hubert and Jan. This complex and colorful polyptych is larger than 11-feet-by 15 feet. A five-year restoration on the piece began in September 2012, during which two-thirds of the artwork will be displayed while the missing panels will be swapped for black-and-white replicas.

St. Mary’s Church holds the 16th-century Veit Stoss “Altarpiece,” the largest Gothic altarpiece in the world at 42 feet high and 36 feet wide. The carved gilt figures are 12 feet tall. Then, go to the Czartoryski Museum to see Leonardo da Vinci’s “Lady with an Ermine,” a portrait of Cecilia Gallerani, mistress of the Duke of Milan.