Pinwheel Forest a forest located west of Nacrene City. Until you get the Basic Badge, you'll only be able to explore the outer area of the forest. Once you've defeated the Nacrene City Gym, you travel here with Burgh to take back the stolen Dragon Skull Fossil from Team Plasma. After defeating Team Plasma you can continue your journey by heading northwards to the Skyarrow Bridge.
In Pokémon Black and White, Virizion can be captured in the Rumination Field after Cobalion has been fought in the Guidance Chamber in the back of the Mistralton Cave.
Rumination Field is an area where the Legendary Pokémon Virizion can be captured in Pokémon Black and White. It can be found in the northeast corner of the interior of Pinwheel Forest. Boulders block its path until the player has fought Cobalion in the Guidance Chamber at the back of the Mistralton Cave.