  We suggest a method for engineering a quantum walk, with cold atoms as
walkers, which presents topologically non-trivial properties. We derive the
phase diagram, and show that we are able to produce a boundary between
topologically distinct phases using the finite beam width of the applied
lasers. A topologically protected bound state can then be observed, which is
pinned to the interface and is robust to perturbations. We show that it is
possible to identify this bound state by averaging over spin sensitive measures
of the atom's position, based on the spin distribution that these states
display. Interestingly, there exists a parameter regime in which our system
maps on to the Creutz ladder.
