The Eurostar is really a very useful invention to connect the UK with the rest of the European continent. It drives you safely under the sea through a tunnel and 20 min later you are on the other side both ways. For people who want to visit London or the North of the UK it is really very, very practical and quick. It takes you exactly 3 h from Brussels to London, the train running at 300 km/h (186 mph) on a network of high-speed lines.
It only becomes an adventure when you want to go to the South East coast of England ! read more here