NEW: Scientists claim they've discovered massive vertical cylinders undeath the Giza pyramids, extending nearly a half-mile deep underground.

Italian and Scottish researchers claim they've discovered "a vast underground city" under the pyramids.

Using Synthetic Aperture Radar (SAR) technology, scientists say they've discovered massive cylinders going 2100 feet below the pyramids.

The cylinders converge into multiple cube-shaped structures that are 80x80 square meters.

Some scientists are pushing back on the development, arguing that it's impossible for the radar technology to penetrate that deep into the ground.