  Artificial spin ice offers the possibility to investigate a variety of
dipolar orderings, spin frustrations and ground states. However, the most
fascinating aspect is the realization that magnetic charge order can be
established without spin order. We have investigated magnetic dipoles arranged
on a honeycomb lattice as a function of applied field, using magnetic force
microscopy. For the easy direction with the field parallel to one of the three
dipole sublattices we observe at coercivity a maximum of spin frustration and
simultaneously a maximum of charge order of magnetic monopoles with alternating
charges $\pm$ 3.
