It's cold, it's very, very noisy, and-if I can be quite honest with you-I'm not feeling super relaxed. I'm currently around 300 meters, or 1,000 feet, beneath the North Sea, in a dark, dank cave. It smells weird. And I am increasingly aware of the pressure from millions of tons of seawater just above my...

This is today's edition of The Download, our weekday newsletter that provides a daily dose of what's going on in the world of technology. Inside the world's deepest and longest subsea road tunnel -Niall Firth I'm currently around 1,000 feet beneath the North Sea, in a dark, dank cave. It smells weird. And I'm increasingly...