Lebrun, P 2000 2000 Key technologies to the Large Hadron Collider (LHC), the 26.7 km circumference high-energy, high-luminosity particle collider under construction at CERN, are high-field superconducting magnets and superfluid helium cryogenics. After recalling the main challenges of the project, we present the rationale for applying these technologies on an unprecedented scale and briefly indicate the status of their implementation.