  While the experimental progress on three dimensional topological insulators
is rapid, the development of their two dimensional counterparts has been
comparatively slow, despite their technological promise. The main reason is
materials challenges of the to date only realizations of two-dimensional
topological insulators, in semiconductor quantum wells. Here we identify a two
dimensional topological insulator in a material which does not face similar
challenges and which is by now most widely available and well-charaterized:
graphene. For certain commensurate interlayer twists graphene multilayers are
insulators with sizable bandgaps. We show that they are moreover in a
topological phase protected by crystal symmetry. As its fundamental signature,
this topological state supports one-dimensional boundary modes. They form
low-dissipation quantum wires that can be defined purely electrostatically.
