Mount Koya: is it worth the trek?

I am visiting Japan soon, and I am trying to see if I can wedge Koyasan into our trip, because it seems like a great experience. So far it seems to be very inconvenient for our itinerary, though. Is it a must-see, must-do experience, or is it a little overrated?

If you decide to go, definitely stay at one of the temple accommodation and have dinner & breakfast there. I personally think that this is the main attraction of Koyasan. The cemetery is also very scenic.

You will essentially need 2 days for the trip out to Koyasan. It is your decision if cutting out something else from your trip makes sense to you.
Just my personal advise, if you have planned to stay any time at Osaka, cut that down to 0 in favor of Koyasan.

Enjoy your trip to Japan!

Visiting Koyasan is definitely worthwhile - the town is fascinating and the stay in the monastery lodgings was definitely the high light. We were lucky enough to arrive on the eve of the anniversary celebrations of Kukai's (Kobo Daishi) Nirvana so we were able to take part in the festivities and watch various processions.
We had looked forward to our visit to Koyasan as it promised to be very different to our other experiences of Japan - and it didn't disappoint!
In November, we will be making our 6th trip to Japan and I would definitely say that our trip to Koyasan was one of the highlights of all our trips.

I think it really depends on the person and expectations. If the more religious side of Japan interests you, then it's probably worth the treck. The biggest complaint I've heard about here is normally from people who expect Koyasan to only be filled with Japanese pilgrims and then are disappointed when they find that they temple lodging is mainly filled with Western Tourists.

For me, I find that it's a great place to experience a temple lodging which is english friendly. Okunoin is also quite nice and worth a visit as well. The main problem with the Kansai region is the large amount of high quality temples. Don't forget that most people do get temple fatigue. The temples at Koyasan are not as impressive as those in Kyoto or Nara, but are different.

From memory, I have posted photos of what to do in Okunoin on my JG profile page. If interested, go to it and search for Koya - it will probably be in the middle of the main posts....

We just came back from a rainy Koyasan. It takes roughly half a day to get there and another half day to get back. Whether it is worth that effort?
Yes, because the cemetary is amazing, even in the rain. And the surrounding nature is beautifull.
The temple lodging in my opinion is a bit of a rip off, crazy expensive for what you get. Very commercial, didn't feel very spiritual. And only western tourists.