Here's a picture of Our Lady of Guadalupe, inside the Basilica of the National Shrine of the Immaculate Conception in the Great Upper Church. As the story goes, Mary appeared to Juan Diego, a peasant, in December of 1531 and asked him to go ask the bishop to have a temple built where she stood. When the bishop asked for proof of a miracle, Juan Diego went back to Mary, who arranged some roses in his cloak and told him to carry the roses, leaving them exactly as Mary had arranged them. When Juan Diego opened up his cloak to show the bishop the roses, he was startled to see the bishop and his attendants kneeling before him - a glowing, life size figure of Mary had been transferred to Juan Diego's cloak. The same cloak can still be seen today and to this day, there is no explanation as to how the image lasted this long, or as to how it was painted (including the paint used, etc.). At least it wasn't a grilled cheese sandwich.
You can go to the Basilica anytime during the day (Sunday is probably not a good day, since mass will be celebrated throughout the day), and they offer guided tours or you can do as I like to do and just walk around. Even if you aren't Catholic, it is one of the often missed aspects of Washington DC that is worth seeing. It's numbered among the 10 largest churches in the world and has many different chapels inside reflecting the many different cultures, and many different visits of Mary. In the crypt church, there is also the Hall of American Saints, which include Frances Xavier Cabrini (Mother Cabrini of NYC), Elizabeth Ann Seton (of Emmitsburg, MD), Kateri Tekakwitha (the "Lily of the Mohawks"), Rose Philippine Duchesne (of St. Louis, MO), and St. Katharine Drexel (an heiress, from Philadelphia, PA).
