These are not exactly time travel maps but you can views maps that show how the area you live in has developed over time one after the other plus get various stats. Time portals are not marked sadly but you can always go and look for your own
This may also be used as a reference to house prices. In new york, the further your house is from the city (after a cut off point) is in direct proportion to it's value. I think it was $10,000 per 10 miles. there are some very cheap homes for sale upstate new york.
You can get a custom one from a certain start point at Mapumental (http://www.mysociety.org/projects/mapumental/). You need to sign up for a login, but once you've got one it's amazing.
Put in where you want to work, how much you can afford to spend on a house and how scenic you want the area to be and bingo - an instant heatmap of where you should look for a house.
If anyone wants I can use my login to make them one.