8. English Channel Tunnel
Image Source: jespahjoy
Also known as the “Chunnel,” this massive project linked Great Britain to mainland Europe, and is the second-longest tunnel in the world. It was finished in 1994 after 6 years of construction that involved 13,000 people and 11 massive tunnel-boring machines. It is 31 miles in length and allowed high-speed train service to be established between England and France.
