Unused / demolished railways

Hi,
Is there anywhere to find out about unused and / or demolished railways in Japan?

I saw some pictures of an old railway on Yakushima, maybe it is an old mining railway, not sure. But mostly interested in regular railways for freight and people.

https://en.wikipedia.org/wiki/List_of_defunct_railway_companies_in_Jap...

There are many railway museums dotted across the country. Since these deal with history also. You will find information about old closed down lines and previous used freight lines and services.

The smaller museums are normally much better for this historical information.

http://www.ncnrm.com/
http://www.tsuyamakan.jp/en/index.html
http://www.k-rhm.jp/

How about this?

http://rail-mtb.com/en/

Some have been partially preserved. For example you can bike along the Katatetsu Roman Kaido:
http://bromptonjapan.com/katatetsu-roman-kaido-cycling-road-in-okayama...

There is also a small museum for the former Ikasa Tetsudo (Railway):
https://www.city.kasaoka.okayama.jp/soshiki/28/ikasatetudou.html