  Hen 3-160 is reported in Belczynski et al.'s (2000) catalog as a symbiotic
binary system with M7 giant donor. Using $V$- and $I$-band photometry collected
over 20 years we have found that the giant is a Mira variable pulsating with
242.5-day period. The period-luminosity relation locates Hen 3-160 at the
distance of about 9.4 kpc, and its Galactic coordinates ($l=267.7^{\circ}$,
$b=-7.9^{\circ}$) place it $\sim$1.3 kpc above the disc. This position combined
with relatively high proper motions (pm$_{\rm{RA}}=-1.5$ mas yr$^{-1}$,
pm$_{\rm{DEC}}=+2.9$ mas yr$^{-1}$, Gaia DR2) indicates that Hen 3-160 has to
be a Galactic extended thick-disc object. Our red optical and infrared spectra
show the presence of ZrO and YO molecular bands that appear relatively strong
compared to the TiO bands. Here we propose that the giant in this system is
intrinsic S star, enriched in products of slow neutron capture processes
occurring in its interior during an AGB phase which would make Hen 3-160 the
first symbiotic system with Mira variable S star.
