In-ground structures are constructions that are built below the surface of the ground. These can include items like basements, underground parking garages, and tunnels. They are designed to utilize space efficiently and can provide protection from weather and natural disasters. These structures often require careful planning and engineering to ensure stability and safety. They may involve excavation and the use of materials that can withstand soil pressure and moisture. In-ground structures are commonly used in urban areas where space is limited and can enhance the functionality of buildings and infrastructure.