  We describe the invariant metrics on real flag manifolds and classify those
with the following property: every geodesic is the orbit of a one-parameter
subgroup. Such a metric is called g.o. (geodesic orbit). In contrast to the
complex case, on real flag manifolds the isotropy representation can have
equivalent submodules, which makes invariant metrics depend on more parameters
and allows us to find more cases in which non-trivial g.o. metrics exist.
