1. Since Antiquity

Since prehistoric times and the "caveman", all civilizations have made varying degrees of use of the subsoil, either to extract resources (water, flint for tools, minerals and building materials), or as shelter and hiding places for families and their possessions.

Without going back to the Etruscans and ancient Rome (the Forum sewer is attributed to Tarquin the Superb, four centuries before our era, and most aqueducts were built underground), it should be noted that use of the urban subsoil remained modest until the mid-19th century (see table 1 ); the 20th century saw the simultaneous growth of cities and automobile traffic, the latter enabling the former and the former requiring...