  We present the main characteristics of the proposed location for the
Javalambre Astrophysical Observatory. The measurements have been obtained from
spectrophotometric, photometric and seeing data obtained with different
monitors and instruments on the site and publicly accessible meteorological
satellite data.
  The night-sky optical spectrum observed in a moonless night shows very little
contamination by the typical pollution lines. Their contribution to the
sky-brightness is ~0.06 mag in B, ~0.09 mag in V and ~0.06 mag in R. In
particular, the comparison of the strengths of the Sodium artificial and
natural lines indicates that the site satisfies the IAU recommendations for a
dark site. The zenith-corrected values of the moonless night-sky surface
brightness are B = 22.8 mag arcsec^-2, V = 22.1 mag arcsec^-2, R = 21.5 mag
arcsec^-2, I = 20.4 mag arcsec^-2, which indicates that the site is very dark.
The extinction has been measured for the summer period, with a typical value of
0.22 mag in the V-Band, with the best measured value of 0.18 mag in a totally
photometric night. The median value of the seeing in the V-band for the last
two years (2008-9) is 0.71", with a mode of 0.58". The seeing values present a
seasonal pattern, being smaller in summer (~0.69") than in winter time (0.77").
For 68% of the analyzed nights the seeing was better than 0.8" during the
entire night. The seeing is found to be stable for rather long periods, in
particular for the nights with good seeing values. The typical scale, for
nights with the seeing below 0.8", is about 5 hours for variations within 20%
of the reference value. The fraction of totally clear nights is ~53%, while the
fraction of nights with at least a 30% of the night clear is ~74%.
