  Open clusters older than $\sim4$ Gyr are rare in the Galaxy. Affected by a
series of mass-decreasing processes, the stellar content of most open clusters
dissolves into the field in a time-scale shorter than $\sim1$ Gyr. In this
sense, improving the statistics of old objects may provide constraints for a
better understanding of the dynamical dissolution of open clusters. Isochrone
fits indicate that FSR 1716 is more probably an old ($\sim7$ Gyr) and absorbed
($\aV=6.3\pm0.2$) open cluster, located $\approx0.6$ kpc inside the Solar
circle in a contaminated central field. However, we cannot rule out the
possibility of a low-mass, loose globular cluster. Czernik 23 is shown to be an
almost absorption-free open cluster, $\sim5$ Gyr old, located about 2.5 kpc
towards the anti-centre. In both cases, Solar and sub-Solar ($[Fe/H]\sim-0.5$)
metallicity isochrones represent equally well the stellar sequences. Both star
clusters have a low mass content ($\la200 \ms$) presently stored in stars.
Their relatively small core and cluster radii are comparable to those of other
open clusters of similar age. These structural parameters are probably
consequence of the several Gyrs of mass loss due to stellar evolution, tidal
interactions with the disk (and bulge in the case of FSR 1716), and possibly
giant molecular clouds. Czernik 23, and especially FSR 1716, are rare examples
of extreme dynamical survivors. The identification of both as such represents
an increase of $\approx10%$ to the known population of open clusters older than
$\sim4$ Gyr in the Galaxy.
