We discuss some of the classical and quantum geometry associated to th
e degeneration of cycles within a Calabi-Yau compactification. In part
icular, we focus on the definition and properties of quantum volume, e
specially as it applies to identifying the physics associated to loci
in moduli space where non-perturbative effects become manifest. We dis
cuss some unusual features of quantum volume relative to its classical
counterpart. (C) 1997 Elsevier Science B.V.