  For every proper geodesic space $X$ we introduce its quasi-geometric boundary
$\partial_{QG}X$ with the following properties: 1. Every geodesic ray $g$ in
$X$ converges to a point of the boundary $\partial_{QG}X$ and for every point
$p$ in $\partial_{QG}X$ there is a geodesic ray in $X$ converging to $p$, 2.
The boundary $\partial_{QG}X$ is compact metric, 3. The boundary
$\partial_{QG}X$ is an invariant under quasi-isometric equivalences, 4. A
quasi-isometric embedding induces a continuous map of quasi-geodesic
boundaries, 5. If $X$ is Gromov hyperbolic, then $\partial_{QG}X$ is the Gromov
boundary of $X$. 6. If $X$ is a Croke-Kleiner space, then $\partial_{QG}X$ is a
point.
