You would travel in a Northwestern direction, and would go over the English Channel.
It depends where your starting point is.
You'd need to cross the English Channel to go from London to Paris. If you're going by rail, you cannot cross OVER the Channel - but you can cross UNDER it. To Vienna, you'll cross a great number of rivers, but the most important is probably the Rhine. Lots of bridges that way.
The Atlantic Ocean if you want to get there earlier.
If you traveled from Bangor, Maine to London, England, you would cross the Atlantic Ocean.
The North Sea
English channel
the Seine river runs through Paris
London Bridge spans the River Thames.
to cross over a body of water
south america
The Seine River.
the Thames river