Cities currently house more than half of the world's population, and by 2050, this number is expected to rise dramatically. With increasing urbanization, cities face significant challenges, including the need for sufficient and appropriate infrastructure, particularly transportation infrastructure. Besides, public owners are taking the environmental impact of their projects more and more seriously, and as a result, both designers and contractors need to tackle this arising concern and find solutions to increase resiliency of their projects. In this context, tunnelling offers an underground alternative to standard surface transport networks , providing new space in saturated areas and opening the door to exploring more resilient and sustainable ways of urbanism. Designing a new path into this transformation will however imply a social mindset change. Advanced construction techniques help minimize surface disturbance and habitat disruption. Real-time monitoring systems together with artificial intelligence and predictive analytics are being used to optimize maintenance schedules and detect potential issues before they escalate. A new construction era begins and possibilities offered by the underground are yet to be rediscovered.