2 days left - what to do

Hi,
I just wanted to get some help from the forum community.
In my itinerary there are 2 unplanned days left, would like to get some ideas where to go.
On 22. Oct we will wake up in the morning in Koya-san and have two full days ( 22,23 ) to spend somewhere. On 24.Oct at 2pm Haneda Airport we are flying back home.

Till this time we will already visit : Tokyo, Nikko, Kyoto, Nara, Osaka, Himeji Castle.

I was hoping to go to Kamikochi but just realized it will take full day to get there, which leaves just 1 day for hiking. Is there any nice place near Koya-san - Tokyo which we can get to and do some nice hiking? What about Fuji National Park (unfortunately we can't hike Fuji in Oct)
Thanks!

It is not you cannot hike Fuji. Just more dangerous as it starts to get cold. Though, you won't get snowfall till later.

I would recommend Uji & Ise. You are a fan of Onsens than Arima Onsen, Kinosaki Onsen + Amanohashidate, or Kii-Katsura's Urashima Hotel are some options to consider.

If climbing mountains is a must than hiking Mt Rokko range in Kobe is an option. It is not a wild mountain, but this is part of its attractiveness. A small cafe, a stream, a herb garden, and a waterfall. Atop is a view of Osaka and Kobe. To tell the truth I do not know where Osaka ends and Kobe starts. They seem to have merge. On a clear day, Kansai Airport and planes can be seen in the distance. Night view is pretty impressive too.

Are you using a rail pass? Or is budget an issue? If on a rail pass than relaxing in Kinosaki Onsen is what I would do. A more expensive but worthwhile choice would be to go to Hiroshima and stay the night in a Ryokan in Miyajima. Both trips can be done in a day thanks to the fast Japanese trains.

Another place to consider would be to go to Kanazawa. It takes a while to get from Kyoto and should not be attempted without a Rail Pass (Japan Rail or Hokuriku). It has one of Japan's greatest landscape gardens and a huge castle. (I think it is the best garden after Ryoanji's) (Himeji castle is pretty but not big)

Lastly, how about just booking a hotel for Kyoto? If you enjoy the city, as many JG forum users have, you can continue touring around it. If it displeases you, a day trip to Uji & Ise is possible. So is a day trip to Kanazawa or Hiroshima. (Though you would have to take the first and last trains to maximise your time)

Nagano or Niigata is also beautiful.

Echigoeuzawa for the sake onsen.

Our favourite place to finish a holiday (now that we depart from Narita) is Enoshima. It is handy to Tokyo and Narita (don't know about Haneda), the island is really pretty, there are views of Mt Fuji early in the morning, and then you can hop on the tram and rattle along the sea road to get into Kamakura.
We generally devote a whole day to the various parts of Kamakura (there are some "hidden" gems, or at least not quite as popular gems), then about a half day to walk over the top of Enoshima to the caves and have a potter around, there is a great Italian restaurant up near the lighthouse with just awesome food, and views out over the ocean.

We have stayed there a few times, it is a lot of fun. Our favourite place to stay is Iwamotoro Honkan.

Given how handy it is to the airports, it is a really great way to finish up a holiday without spending it in the city.