  Although the multimessenger detection of the neutron star merger event
GW170817 confirmed that mergers are promising sites producing the majority of
nature's heavy elements via the rapid neutron-capture process ($r$-process), a
number of issues related to the production of translead nuclei -- the actinides
-- remain to be answered. In this short review paper, we summarize the general
requirements for actinide production in $r$-process and the impact of nuclear
physics inputs. We also discuss recent efforts addressing the actinide
production in neutron star mergers from different perspectives, including
signatures that may be probed by future kilonova and $\gamma$-ray observations,
the abundance scattering in metal-poor stars, and constraints put by the
presence of short-lived radioactive actinides in the Solar system.
