The Church at Auvers

 was a painting by Vincent van Gogh which alerted the Doctor to a threat bearing down on van Gogh's village in 1890. When he and Amy Pond viewed the painting in 2010 at the Musée d'Orsay, he noticed an evil creature painted into one of its windows. He therefore immediately traveled to visit van Gogh and rid the town of the monster. Once the being was dispatched, the painting hanging in the Musée d'Orsay no longer had a monster in its windows. (DW: Vincent and the Doctor)
 * ''The painting is never actually named in the episode, but it is sufficiently iconic in real life that it arguably needn't have been explicitly named to be recognized by name.