Summary:

- The article discusses the discovery of a "lost city" deep beneath the Earth's surface, revealed by the longest mantle core ever drilled. This lost city is believed to be a remnant of an ancient tectonic plate that was subducted and buried under the Earth's surface.

- The drilling project, led by a team of international scientists, has provided unprecedented access to the Earth's mantle, allowing them to study the structure and composition of this hidden realm in unprecedented detail.

- The findings from this project have the potential to shed new light on the processes that shape the Earth's interior and the evolution of our planet over geological timescales, offering valuable insights into the complex workings of our dynamic planet.