We recently discovered GOOGLE EARTH. It is a free downloadable program that can take you in 3D any where across the globe! My four year old boy has had so much fun flying like and airplane over mountains and speed boating across the ocean.

We have visited The Statue of Liberty, The Ancient Pyramids in Egypt, The Grand Canyon, Iceland, Russia, The Effle Tower, Niagara Falls, Big Ben and more. Without cracking a book he has learned about these places just my exploring with Google Earth!

I often let him use Google Earth during his sister's nap time.
There are other features we have to still play with like the Flight Simulator, Going to Mars, and others. As with most online stuff the options are endless.
The nice thing is we learn more and more with each option!