 Wildlife Conservation Society has a very cool project happening using historic maps to determine what New York City, Manhattan in particular looked like in 1609 when Henry Hudson sailed up for the first time. So Sam came and did the same work with the fourth grade teachers instead of focusing on interior landforms. They focused on coastal landforms. So they thought about peninsulas and coves and bays and the river system so that that's all very immediately transferred to New York City and New York State geography, and it leads the kids very nicely into fifth grade. And then they looked at historic maps of early colonial New Amsterdam and New York. The kids are working in partnerships. We put transparencies over the flat version and then we actually go over where the rivers were, where the bluffs were, where the canyons are, where the coast is, so that they get a three-dimensional view on this flat map of what it was like before the skyscrapers. And also where our school is, where their houses are in relation to this. And then we look at it next to Manhattan now. What's happening now? What happened then? Right, and since you did it on transparency, you can take this and lay it on top and you can see how the shape of Manhattan has changed over time because you can see that all the hills that were down on the Lower East Side are flattened and the marshes are filled in and the coastline has changed and the rivers are paved over and you can see all that stuff on the map.