Hamiltonian cycles (seen as **spanning polygons**) are interesting for several reasons (only a few of which I am aware of), but especially because *not* every connected graph has a Hamiltonian cycle (is Hamiltonian), so the characterization of Hamiltonian graphs becomes interesting (see wikipedia article on [Hamiltonian paths][1]). Side note: Each platonic and archimedian solid is Hamiltonian. What about **spanning polytopes**, as one possible generalization of Hamiltonian cycles = spanning polygons? (By "spanning polytope" I mean a spanning subgraph that is the 1-skeleton of a polytope of arbitrary dimension.) There are connected graphs without spanning polytopes (trees obviously), but there are non-Hamiltonian graphs that have a spanning polytope of dimension d>2, e.g. the [Herschel graph][2]. A google search for "spanning polytope" yields only unrelated results, so my question is: > Is there research on this or a related > topic, only under another name? If not so, does this have an obvious - or not so obvious - reason? [1]: http://en.wikipedia.org/wiki/Hamiltonian_path#Bondy.E2.80.93Chv.C3.A1tal_theorem [2]: http://mathworld.wolfram.com/HerschelGraph.html