  We study the transport through evanescent waves in graphene quantum dots of
different geometries. The transmission is suppressed when the leads are
attached to edges of the same majority sublattice. Otherwise, the transmission
depends exponentially on the distance between leads in rectangular dots, and as
a power law in circular dots. The transmission through junctions where the
transmitted and reflected currents belong to the opposite valley as the
incoming one depends on details of the lattice structure at distances
comparable to the atomic spacing.
