David Rumsey is one of the world's great map collectors, and he has been very generous by sharing his treasures via the David Rumsey Map Collection website. Recently, Rumsey has selected 120 historical maps from his collection to link up with data from Google Maps and Google Earth. These maps are tremendous repositories of historical and cultural information by themselves, and when they are joined up with the other maps, they present a multifaceted way of visualizing the past, present, and future of these locales. As the website notes, this is "a marriage of historic cartographic masterpieces with innovative contemporary software tools." First-time visitors can read the explanation of how this is done, and then scroll down to look through the list of maps, which includes Chicago in 1857, Moscow in 1836, Kyoto in 1709, and a celestial globe from 1792. Also, visitors can toggle the satellite view via the Google Maps overlay map in order to compare and contrast the changes that have occurred over the past decades and centuries.