The Dawn Stone is an evolutionary stone introduced in Generation IV. It is found on Route 8 in a secret area located behind a tree that can be cut. It can be used on a male Kirlia to evolve it into Gallade and female Snorunt into Froslass. The Dawn stone can be found in route 8 next to the grass patch in a wall.
It is near the middle of route 8 and there should be tree that can be cut down. Then you find a secret place and on the
bridge is the dawn stone.