  We present a catalog of sources detected above 50 GeV by the {\it
Fermi}-Large Area Telescope (LAT) in 80 months of data. The newly delivered
Pass 8 event-level analysis allows the detection and characterization of
sources in the 50 GeV--2 TeV energy range. In this energy band, {\it Fermi}-LAT
has detected 360 sources, which constitute the second catalog of hard {\it
Fermi}-LAT sources (2FHL). The improved angular resolution enables the precise
localization of point sources ($\sim$1.7$'$ radius at 68 % C.~L.) and the
detection and characterization of spatially extended sources. We find that 86 %
of the sources can be associated with counterparts at other wavelengths, of
which the majority (75 %) are active galactic nuclei and the rest (11 %) are
Galactic sources. Only 25 % of the 2FHL sources have been previously detected
by Cherenkov telescopes, implying that the 2FHL provides a reservoir of
candidates to be followed up at very high energies. This work closes the energy
gap between the observations performed at GeV energies by {\it Fermi}-LAT on
orbit and the observations performed at higher energies by Cherenkov telescopes
from the ground.
