The moduli space of principally polarized Abelian varieties with real structure and with level N = 4m structure (with m≥1) is shown to coincide with the set of real points of a quasi-projective algebraic variety defined over ${\open Q}$, and to consist of finitely many copies of the quotient of the space GL(n, ${\open R}$)/O(N) (of positive definite symmetric matrices) by the principal congruence subgroup of level N in GL(n, ${\open Z}$).