TRULY STRONG-COUPLING AND LARGE RADIUS IN STRING THEORY

String theory, if it describes nature, is probably strongly coupled. I n light of recent developments in string duality, this means that the ''real world'' should correspond to a region of the classical moduli s pace which admits no weak coupling description. We exhibit, in the het erotic string, one such region of the moduli space, in which the coupl ing, lambda, is large and the ''compactification radius'' scales as la mbda(1/3). We discuss some of the issues raised by the conjecture that the true vacuum lies in such a region. These include the question of coupling constant unification, and more generally the problem of what quantities one might hope to calculate and compare with experiment in such a picture.