Eric Sanderson pictures New York’s Natural History

400 years after Hudson found New York harbor, Eric Sanderson shares how he made a 3D map of Mannahatta’s fascinating pre-city ecology of hills, rivers, wildlife — accurate down to the block — when Times Square was a wetland and you couldn’t get delivery.

Armed with an 18th-century map, a GPS and reams of data, Eric Sanderson has re-plotted the Manhattan of 1609, just in time for New York’s quadricentennial.