Mount Kōya is a mountain in Wakayama prefecture to the south of Osaka, Japan, primarily known as the headquarters of the Shingon sect of Japanese Buddhism. First settled in 816 CE by the monk Kūkai as a retreat far away from the courtly intrigues of Kyoto, Mt. Koya is located in a 800-m-high valley amid the 8 peaks of the mountain. The original monastery has grown into the town of Koya, featuring a university dedicated to religious studies and over 100 temples, many of which offer lodging to pilgrims.
In 2004, UNESCO designated Mt. Koya as part of a wider World Heritage Site.
Hiking around Mount Koya is a good option. Among many courses, there is one that starts at Daimon, hiking up to a tiny shrine at the top of Bentengaku, and then down to Nyonindou.