  The geometrical intrinsic contribution to the anomalous Hall conductivity
(AHC) of a metal is commonly expressed as a reciprocal-space integral: as such,
it only addresses unbounded and macroscopically homogeneous samples. Here we
show that the geometrical AHC has an equivalent expression as a local property.
We define a "geometrical marker" which actually probes the AHC in inhomogeneous
systems (e.g. heterojunctions), as well as in bounded samples. The marker may
even include extrinsic contributions of geometrical nature.
