Above: Los Angeles and New York City 280 million years ago, at the time of the first land animals.
This is Ancient Earth, a map that uses data from the PALEOMAP Project to track the planet's distribution of land and water through time, all the way back to 750-million years ago. You can enter any city and choose how many million years ago you'd like to look back (or choose the time of a major events like the first shells, land plants, dinosaur extinction, first primates, hominids, etc), and it will show you what your area of the world looked like then. Obviously, it doesn't serve much practical purpose for non-paleontologists other than knowing where you can safely land a time machine, because there's nothing worse than traveling back to the Cretaceous period just to almost drown in the middle of an ocean you didn't know was going to be there when you assumed you were going to land safely in the middle of a t-rex sex party. I thought I was a goner, I really did.
Thanks to Closet Nerd, who's going to see the new (now already old) Star Wars movie today. Pfft, some fan you are -- what took so long?! (I'll meet you at the theater fifteen before showtime)