  We present high spatial resolution ($\approx24$ pc) Atacama Large
Millimeter/sub-millimeter Array $^{12}$CO(2-1) observations of the central
region of the nearby barred spiral galaxy NGC 5806. NGC 5806 has a highly
structured molecular gas distribution with a clear nucleus, a nuclear ring and
offset dust lanes. We identify $170$ spatially- and spectrally-resolved giant
molecular clouds (GMCs). These clouds have comparable sizes ($R_{\mathrm{c}}$)
and larger gas masses, observed linewidths ($\sigma_{\mathrm{obs,los}}$) and
gas mass surface densities than those of clouds in the Milky Way disc. The size
-- linewidth relation of the clouds is one of the steepest reported so far
($\sigma_{\mathrm{obs,los}}\propto R_{\mathrm{c}}^{1.20}$), the clouds are on
average only marginally bound (with a mean virial parameter
$\langle\alpha_{\mathrm{vir}}\rangle\approx2$), and high velocity dispersions
are observed in the nuclear ring. These behaviours are likely due to bar-driven
gas shocks and inflows along the offset dust lanes, and we infer an inflow
velocity of $\approx120$ kms$^{-1}$ and a total molecular gas mass inflow rate
of $\approx5$ M$_\odot$ yr$^{-1}$ into the nuclear ring. The observed internal
velocity gradients of the clouds are consistent with internal turbulence. The
number of clouds in the nuclear ring decreases with azimuthal angle downstream
from the dust lanes without clear variation of cloud properties. This is likely
due to the estimated short lifetime of the clouds ($\approx6$ Myr), which
appears to be mainly regulated by cloud-cloud collision and/or shear processes.
Overall, it thus seems that the presence of the large-scale bar and gas inflows
to the centre of NGC 5806 affect cloud properties.
