In an ambitious project that looks like a cross between a green Millennium Falcon and a villain's lair from a James Bond movie, France's EuropaCity is nothing less than a self-contained underground city, only part of it sticks up from the surrounding landscape.
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." -- Mark Twain