For the Romans, it was a horrible sea crossing. The Spanish navy never ruled it. Hitler was thwarted in his desired to cross it. Having just ridden in comfort underneath the English Channel on the Eurostar train in about 25 minutes, I am reminded of the history of the fields of Northern France. We do truly live in an amazing age. The Eurostar experience, by the way, is quite nice: security screening and boarding is more civilized than the usual airport routine, the seating is nicer, and the food and wine slightly better. You handle your own luggage getting on and off your coach, and the walk through the stations is far shorter than getting to that far distant gate at the airport. At the London end, St. Pancras International station, in the heart of the city, is clean, easily-accessible, and new. In Paris, you arrive at the Gare du Nord train station and have easy access to the Metro and RER trains. Door-to-door, for me, was about 3 hours; an excellent journey.