It provides consistent output and can lower energy bills. Major city set to tap into limitless underground energy source — ...

The man (not named in reports from the time) sledgehammered his wall and found a tunnel behind it, and beyond that, more tunnels. Exploration would later reveal it was an underground city up to 18 ...

A fatberg described as equivalent in size to a blue whale - the largest animal known to have existed - has been removed from ...

Credit: Youtube Helsinki’s underground city, built into solid bedrock, includes gyms, shops, and even a church. It’s designed to house 600,000 people in an emergency.

Officials have announced construction of the Music City Loop, an underground tunnel project by Elon Musk’s Boring Company, ...