Nara Prefecture is located in the Kansai region of Honshu island, the main island of Japan, in the center of the Kii Peninsula. Nevertheless, it is one of only eight landlocked prefectures. Most of the prefecture is covered by mountains and forests.
The Japan Median Tectonic Line (MTL) is running through the prefecture east to west, along the Yoshino River. On the northern side active faults running north to south are still shaping the landscape. On the southern side are the Kii Mountains. The northern side is called Inner Zone, while the southern is called the Outer Zone.
The northern side has north to south running mountain ridges with the Nara Basin inbetween, which is the most heavily populated and most fertile part of the prefecture. There are no underground sites in this part.
All the caves are located in the Kii Mountains. The tallest mountain in Nara Prefecture is Mount Hakkyō (1,914.6 m asl).