The Usui Pass line is now closed but the rack locos and the bankers that used to work the line are preserved
at this museum.
It opened in 1998 at the site of the former Yokokawa motive power depot.
It is also known a Poppo Town after a cartoon character.
In Yokokawa in Gunma prefecture, north of Tokyo.
From Takasaki change to the local train to Yokokawa.
From the station turn left over the level crossing into the musuem.
The following locomotives are on display: D51-96, DD51-1, DD53-1, EF65-520, EF59-1, EF80-63, EF62-1, EF63-1, EF15-165, EF53-2, EF58-172, EF70-1001, EF30-20, EF63-24, EF63-25, DB20-1, EF63-10, EF63-18, EF62-54, EF42-1, EF63-11, EF63-12. Plus units and narrow guage loco 3950 "Green Breeze".
In addition there are narrow guage and mini-train lines, models, exhibits, demonstration line, locoshed and shop.
Open 09:00-17:00 (16:30 in Winter). Closed new year and Tuesdays.
Also open holiday Tuesdays and during school summer break.
Entry (2009) 500 yen.
Japanese Railway Society Report with pictures
There was a report in JRS magazine, Bullet-in 63.
Wikipedia web page
Museum website (Japanese)