Fuji Cavern (不二洞) is one of the biggest cavern in Kanto. It is 2.2km long and takes about 40 min. for touring inside of the cave. This cavern is still actively growing and you can see how stalactite stone is growing.

Toursit Info.
Addmission: 600 yen. Kids 400 yen.
Open: 8:30 to 17:30 (16:30 in winter) Last entry is 1 hr before close time.

Access
0. at Maebashi Station.
1. use JR Ryomo Line to Takasaki (15 min.)
2. use JR Takasaki Line to Shinmachi (10 min.)
3. use bus to Kamiru Machi (69 min.)
4. use bus to Ueno Mura (33 min.)
5. walk (40 Min.)