A conceptual project envisions vast underground neighborhoods in Seoul to accommodate a population surge after Korean reunification. Integrating existing underground malls and transport links, it aims to densify the city without upward expansion. By excavating below street level, the project minimizes disruption, enhances pedestrian connectivity, and utilizes old bunkers for parks and public spaces.

Source: https://www.dezeen.com/2018/08/10/natasha-marks-bartlett-school-architecture-graduate-concept-seoul-south-north-korea/