We talked about this before here; and the Manhatta project has a nice new interface for exploring the 1609 map of the island of Manhatta(n), block by block, through time. I love this project! The combination of mashup, history, design and art are breathtaking. (And our own Tim Bean worked on reconstructing the early topography! - see his comment below.) Go Fullscreen on your 30"-monitor. I dare you.
“The goal of the Mannahatta Project has never been to return Manhattan to its primeval state. The goal of the project is discover something new about a place we all know so well, whether we live in New York or see it on television, and, through that discovery, to alter our way of life. New York does not lack for dystopian visions of the future…. But what is the vision of the future that works? Might it lie in Mannahatta, the green heart of New York, and with a new start to history, a few hours before Hudson arrived that sunny afternoon four hundred years ago?”
- from Mannahatta: A Natural History of New York City