Jim, you do know you can just click on one of the links above to get you back to that area again, don't you?
Plus, if you do accidentally shut down like that, just go to your browser history and select the last tile entry at the top of the list; it should take you back to where you were. Example below
Apologise if I've misunderstood and you already know all this
Edit: Ok, normally this works fine, but for some reason today it won't take me back to this one http://www.tomnod.com/campaign/antarctica_pilot_2/map/1g2hxmy69. Spoil sports