 I'm not here for the arts. Rather, I'm hunting for hidden pieces of the past. There are fossils all around the city. It turns out many of DC's most famous and intricate buildings, like the National Gallery of Art, are crafted from stone from across the world, which is why fossils from hundreds of millions of years ago are literally in the walls, in the tiles right beneath your feet, or right next to me here in the urinal. We're looking at a cross-section of a snail shell.