  Variational Monte Carlo calculations have been made for the $_{
\Lambda}^{17}$O hypernucleus using realistic two- and three-baryon
interactions. A two pion exchange potential with spin- and space-exchange
components is used for the $\Lambda$N potential. Three-body two-pion exchange
and strongly repulsive dispersive $\Lambda$NN interactions are also included.
The trial wave function is constructed from pair- and triplet-correlation
operators acting on a single particle determinant. These operators consist of
central, spin, isospin, tensor and three- baryon potential components. A
cluster Monte Carlo method is developed for noncentral correlations and is used
with up to four-baryon clusters in our calculations. The three-baryon
$\Lambda$NN force is discussed.
