To visit Koyasan from Osaka, the best way is to buy Koyasan Heritage pass by Nankai Railway if you do not have a JR pass. The regular version of this pass costs about JPY2900 per person and the limited express one cost JPY3500. Train departs from Nankai Namba or Shin-Imamiya station.This pass also allows you to use unlimited bus in Koyasan, it can be very convenient if you do not have time to walk around or if it is too cold. Koyasan is a small town so once you get there just go to the tourist information centre for free wifi and a free map, and walk to Yochiin or other temple lodging around.
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