This morning I took an early train from Osaka to Koyasan (Mount Koya), which is only about 50km south of Osaka, but it takes an about 2 hour ride with two different trains, cable car and bus to get there. Koyasan is the centre of Shingon Buddhism and a sacred place and pilgrimage start and end point. I found the place rather touristic and on a Sunday morning it was quite crowded already, so I have to admit that Japan Guide is right that you should overnight in a temple there to visit the places in the evening or early morning, when normal visitors are absent. However, the Okunoin (inner temple) and especially the about 2km long path up there with graveyards all over was still impressive and fascinating.
Still, it only took about 4 hours to see everything in Koyasan, so I had the late afternoon and evening left for spending some additional time in Osaka. I did a canal cruise and walked around the Namba quarter, the main shopping, entertainment and restaurant district in Osaka, where I enjoyed different kinds of food (a Sashimi and Tempura set, takoyaki with octopus and shrimps, and a “self-service” frozen yoghurt creation).