  Beyond uranium heavy elements rapidly become increasingly unstable with
respect to spontaneous fission as the proton number Z increases, because of the
disruptive effect of the long-range Coulomb force. However, in the region just
beyond Z = 100 magic proton and neutron numbers and the associated shell
structure enhances nuclear stability sufficiently to allow observation of
additional nuclei. Some thirty years ago it was speculated that an island of
spherical, relatively stable superheavy nuclei would exist near the next doubly
magic proton-neutron combination beyond 208:Pb, that is, at proton number Z =
114 and neutron number N = 184. Theory and experiment now show that there also
exists a rock of stability in the vicinity of Z = 110 and N = 162 between the
actinide region, which previously was the end of the peninsula of known
elements, and the predicted island of spherical superheavy nuclei slightly
southwest of the magic numbers Z = 114 and N = 184. We review here the
stability properties of the heavy region of nuclei. Just as the decay
properties of nuclei in the heavy region depend strongly on shell structure,
this structure also dramatically affects the fusion entrance channel. The six
most recently discovered new elements were all formed in cold-fusion reactions.
We discuss here the effect of the doubly magic structure of the target in
cold-fusion reactions on the fusion barrier and on dissipation.
