Quantum duality principle is applied to a study of classical limits of
quantum algebras and groups. For a certain type of Hopf algebras the
explicit procedure to construct both classical limits is presented. Th
e canonical forms of quantized Lie-bialgebras are proved to be two-par
ametric varieties with two classical limits called dual. When consider
ed from the point of view of quantized symmetries, such varieties can
have boundaries that are noncommutative and noncocommutative. In this
case the quantum duality and dual limits still exist while instead of
Lie bialgebra one has a pair of tangent vector fields.