  M-theory suggests the study of 11-dimensional space-times compactified on
some 7-manifolds. From its intimate relation to superstrings, one possible
class of such 7-manifolds are those that have Calabi-Yau threefolds as
boundary. In this article, we construct a special class of such 7-manifolds,
named as {\it K3-Thurston} (K3T) 7-manifolds. The factor from the K3 part of
the deformation space of these K3T 7-manifolds admits a K\"{a}hler structure,
while the factor of the deformation space from the Thurston part admits a
special K\"{a}hler structure. The latter rings with the nature of the scalar
manifold of a vector multiplet in an N=2 $d=4$ supersymmetric gauge theory.
Remarks and examples on more general K3T 7-manifolds and issues to possible
interfaces of K3T to M-theory are also discussed.
