  The European Solar Telescope (EST) is a project aimed at studying the
magnetic connectivity of the solar atmosphere, from the deep photosphere to the
upper chromosphere. Its design combines the knowledge and expertise gathered by
the European solar physics community during the construction and operation of
state-of-the-art solar telescopes operating in visible and near-infrared
wavelengths: the Swedish 1m Solar Telescope (SST), the German Vacuum Tower
Telescope (VTT) and GREGOR, the French T\'elescope H\'eliographique pour
l'\'Etude du Magn\'etisme et des Instabilit\'es Solaires (TH\'EMIS), and the
Dutch Open Telescope (DOT). With its 4.2 m primary mirror and an open
configuration, EST will become the most powerful European ground-based facility
to study the Sun in the coming decades in the visible and near-infrared bands.
EST uses the most innovative technological advances: the first adaptive
secondary mirror ever used in a solar telescope, a complex multi-conjugate
adaptive optics with deformable mirrors that form part of the optical design in
a natural way, a polarimetrically compensated telescope design that eliminates
the complex temporal variation and wavelength dependence of the telescope
Mueller matrix, and an instrument suite containing several (etalon-based)
tunable imaging spectropolarimeters and several integral field unit
spectropolarimeters. This publication summarises some fundamental science
questions that can be addressed with the telescope, together with a complete
description of its major subsystems.
