  The classical Heron problem states: \emph{on a given straight line in the
plane, find a point $C$ such that the sum of the distances from $C$ to the
given points $A$ and $B$ is minimal}. This problem can be solved using standard
geometry or differential calculus. In the light of modern convex analysis, we
are able to investigate more general versions of this problem. In this paper we
propose and solve the following problem: on a given nonempty closed convex
subset of $\R^s$, find a point such that the sum of the distances from that
point to $n$ given nonempty closed convex subsets of $\R^s$ is minimal.
