Although not a "Washington DC" story, I thought my readers might find the largest exhibit of Vatican artifacts outside of Rome both unsual and different. From the Washington Post:
The only exhibit of Vatican artifacts outside the papal capital is on display in an unlikely spot _ the National Museum of Funeral History, an exhibit hall that celebrates coffins, hearses and other ceremonial aspects of death.
The exhibit is designed to recreate the experience of attending a papal funeral. There is a re-creation of a pope lying in state at St. Peter's Basilica, flanked by two members of the Swiss Guard. A mannequin representing the pontiff is clothed in the funeral vestments made for John Paul II; the Swiss Guard figures wear blue and yellow uniforms donated by the corps.