  A compact space $K$ is {\em Valdivia compact} if it can be embedded in a
Tikhonov cube $I^A$ in such a way that the intersection $K\cap\Sigma$ is dense
in $K$, where $\Sigma$ is the sigma-product (= the set of points with countably
many non-zero coordinates). We show that there exists a compact connected
Abelian group of weight $\o_1$ which is not Valdivia compact, and deduce that
Valdivia compact spaces are not preserved by open maps.
