Nokogiri Yama

Nokogiri Yama is located in Chiba prefecture, around 80 km from central Tokyo. 

Places of interest - Nihon-ji (Nihon-ji has a big statue of Buddha sculped in the mountain) and Jigoku Nozoki (Looking down the hell)

Directions by car - Tokyo Wan Aqua line. Make sure to stop at Umihotaru (海ほたる meaning sea firefly) where the tunnel comes up in the middle of the sea. The place has some restaurants and some other attractions. The view is very good depending on the weather. The aqua line is a little costly though. It costs around 4000 yens one-way.

Alternately, you can take 357 to Chiba that will cost you nothing but it will take much longer time. 
You can either go all the way till Nihon ji or stop at the bottom of the hill and take the ropeway up. 
Directions by train - The nearest station is Hamakanaya station. Its 5-10 mins walk to the ropeway.

Thanks to Mr Amit Ashok Khare for this information and photographs.