  This paper aims to study the feasibility of building an Earth-skimming cosmic
tau neutrinos detector, with the aim of eventually identifying the ideal
dimensions of a natural site (mountainvalley) for the detection, with the
energy range to be determined (evidently, the highest possible numbers range
from 1015 eV to 1020 eV), and possibly locate one such site in Algeria. First,
a Monte Carlo simulation of the neutrino-[mountain]matter interaction as well
as the resulting decay of the tau lepton is conducted to determine the optimal
dimensions of the mountain as well as the location of the tau decay in the
valley. Second, a CORSIKA (COsmic Ray Simulation for KAscade) [1] simulation
with the CONEX option is conducted to track the evolution of the almost
horizontal air shower born from the tau lepton. Among the particles produced in
the shower are: electrons, muons, gammas, pions, etc). The study of the spatial
distribution of these particles enables the discovery of the optimal width of
the valley, and consequently, the distance at which to lay the detection
network.
