  The Cherenkov Telescope Array (CTA) will be the next-generation gamma-ray
observatory, investigating gamma-ray and cosmic ray astrophysics at energies
from 20 GeV to more than 300 TeV. The observatory, consisting of large arrays
of imaging atmospheric Cherenkov telescopes in both the southern and northern
hemispheres, will provide full-sky coverage and will achieve a sensitivity
improved by up to an order of magnitude compared to existing instruments such
as H.E.S.S., MAGIC and VERITAS. CTA is expected to discover hundreds of new TeV
gamma- ray sources, allowing it to significantly advance our understanding of
the origin of cosmic rays, to probe much larger distances in the universe, and
to search for WIMP dark matter with unprecedented sensitivity in TeV mass
range.
  The development of CTA is being carried out by a worldwide consortium of
scientists from 32 countries. Consortium scientists have developed the core
scientific programme of CTA and institutes of the Consortium are expected to
provide the bulk of the CTA components. The construction of CTA is overseen by
the CTA Observatory that will in the future manage observatory operations, the
guest observer programme, and data dissemination.
  This talk will review the scientific motivation for CTA, focusing on the key
science projects that form the core programme of research. The talk will
outline the design of CTA, including the science drivers, overall concept,
performance optimization, and array layouts. The current status of CTA,
including sites, prototype telescope progress, and steps forward will also be
described.
