This lecture explores the potentials of underground architecture, focusing on the construction techniques and the relationship with the surrounding soil. It delves into the concept of 'Groundscape' as a new approach to underground design, emphasizing the importance of embracing the natural imperfections and materiality of the earth. Through case studies like the Temppeliaukio Church in Helsinki and the Olympic Stadium in Berlin, the lecture showcases innovative ways to create habitable spaces below the surface while respecting the geological context. It discusses strategies for utilizing excavation methods, integrating natural light, and establishing connections with existing structures to transform underground voids into functional and meaningful environments.