The Eurotunnel
The <a href=https://www.ice.org.uk/what-is-civil-engineering/what-do-civil-engineers-do/the-channel-tunnel>Channel Tunnel</a> (or ‘Eurotunnel’, or ‘chunnel’, even) opened in 1994 and has been carrying passengers back and forth between the UK and Europe ever since then. With trains travelling out of London from St Pancras Station, onwards to destinations such as Paris, Brussels, and Lyon, it is an engineering and transportation success, with some people even using the tunnel to commute.
Prices can be found as low as £25 one way if travelling as a group, or from £29 as a single person, which represents excellent value for money. The trip to Paris takes just 2 hours and 15 minutes, leaving enough time for work or relaxation, reading a book or playing sudoku (which you can <a href=https://play.google.com/store/apps/details?id=com.easybrain.sudoku.android>download here</a>) en route.
Certainly the Eurotunnel is a vast improvement on the choppy, overly-long ferry journeys we used to make. It is one of the greatest achievements of our European alliance, perhaps.