Pinwheel Forest a forest located west of Nacrene City. Until you get the second 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. Virizion can be captured in the Rumination Field after Cobalion is caught in Mistralton Cave.