  We investigate, by numerical lattice simulations, the static quark-antiquark
potential, the flux tube properties and the chiral condensate for $N_f = 2+1$
QCD with physical quark masses in the presence of strong magnetic fields, going
up to $eB = 9$ GeV$^2$, with continuum extrapolated results. The string tension
for quark-antiquark separations longitudinal to the magnetic field is
suppressed by one order of magnitude at the largest explored magnetic field
with respect to its value at zero magnetic background, but is still
non-vanishing; in the transverse direction, instead, the string tension is
enhanced but seems to reach a saturation at around 50 % of its value at $B =
0$. The flux tube shows a consistent suppression/enhancement of the overall
amplitude, with mild modifications of its profile. Finally, we observe magnetic
catalysis in the whole range of explored fields with a behavior compatible with
a lowest Landau level approximation, in particular with a linear dependence of
the chiral condensate on $B$ which is in agreement, within errors, with that
already observed for $eB \sim 1$ GeV$^2$.
