  We compare STM investigations on two hexaboride compounds, SmB$_6$ and
EuB$_6$, in an effort to provide a comprehensive picture of their surface
structural properties. The latter is of particular importance for studying the
nature of the surface states in SmB$_6$ by surface-sensitive tools. Beyond the
often encountered atomically rough surface topographies of {\it in situ},
low-temperature cleaved samples, differently reconstructed as well as
B-terminated and, more rarely, rare-earth terminated areas could be found. With
all the different surface topographies observed on both hexaborides, a reliable
assignment of the surface terminations can be brought forward.
