While frequent travelers don’t bat an eye at the idea of riding the Eurostar any longer, this is not your average train trip. This high-speed train takes you directly between the south of England to France, Belgium, and the Netherlands via the world’s longest undersea tunnel. For 23.5 miles of your trip, you are actually under the English channel at a depth of 246 feet. No, you can’t see fish bobbing around if you look out the window, but it’s still quite thrilling. The tunnel under the Channel, also known as The Chunnel, was completed in 1993 and the Eurostar has been operating since 1994, expanding its destination offerings ever since. Eurostar trains leave from London’s St. Pancras International station several times daily and tickets are affordable and can be purchased online.