  We outline a strategy for future experiments on neutrino and astroparticle
physics based on the use, at different detector mass scales (100 ton and 100
kton), of the liquid Argon Time Projection Chamber (LAr TPC) technique. The LAr
TPC technology has great potentials for both cases with large degree of
interplay between the two applications and a strong synergy. The ICARUS R&D
programme has demonstrated that the technology is mature and that one can built
a large ($\sim$ 1 kton) LAr TPC. We believe that one can conceive and design a
very large mass LAr TPC with a mass of 100 kton by employing a monolithic
technology based on the use of industrial, large volume cryogenic tankers
developed by the petro-chemical industry. We show a potential implementation of
a large LAr TPC detector. Such a detector would be an ideal match for a
Superbeam, Betabeam or Neutrino Factory, covering a broad physics program that
could include the detection of atmospheric, solar and supernova neutrinos, and
search for proton decays, in addition to the rich accelerator neutrino physics
program. In parallel, physics is calling for another application of the LAr TPC
technique at the level of 100 ton mass, for low energy neutrino physics and for
use as a near station setup in future long baseline neutrino facilities. We
present here the main physics objectives and outline the conceptual design of
such a detector.
