  We discuss the physics potential and the experimental challenges of an
upgraded LHC running at an instantaneous luminosity of 10**35 cm-2s-1.
  The detector R&D needed to operate ATLAS and CMS in a very high radiation
environment and the expected detector performance are discussed.
  A few examples of the increased physics potential are given, ranging from
precise measurements within the Standard Model (in particular in the Higgs
sector) to the discovery reach for several New Physics processes
