29/09/2026
What keeps a historic city like Paris working beneath its famous streets?
Paris is known for the Eiffel Tower, the Seine River, historic buildings, bridges, and dense urban streets. But beneath this familiar city is another layer of infrastructure that most people rarely see.
This realistic engineering cutaway explores how the structures above the streets connect with the infrastructure below them, including building foundations, underground Métro infrastructure, utilities, drainage and sewer systems.
Building infrastructure beneath a historic city presents a unique engineering challenge. Engineers must work within an environment that has developed over centuries, while maintaining existing buildings, transportation networks, streets and essential services.
The Paris Métro is an important part of this urban system, carrying passengers through an extensive underground railway network. Above it, roads, buildings and public spaces continue operating every day.
Different engineering disciplines contribute to this environment. Civil engineers work with urban infrastructure and construction. Structural engineers deal with buildings, foundations and structural systems. Transportation engineers work with roads and rail systems. Water engineers deal with drainage, sewerage and other water-related infrastructure.
The goal of this visualization is to make those hidden systems easier to understand.
A city is not just the buildings we see. It is a connected engineering system built from structures, transportation, water infrastructure, utilities and the ground beneath our feet.
This is the engineering behind Paris.
Learn how cities work. Understand the systems. Discover the careers behind them.