Take a tour of London's new super-sleek train system

In 2018, the largest construction project in Europe - a massive renovation to London's Underground known as Crossrail - will finally reach completion.

Serving more than 200 million people each year, Crossrail will feature 10 new train lines, some embedded more than 100 feet into the earth, and connect 30 existing stations via brand-new tunnels.

Here's what the master plan will look like in action.