Tenkawa is an unexplored place in the mountain district of the Kinki region. En-no-gyoja (役行者) is the first person who set on foot in this area as a base of ascetic practices of the Shugendo (修験道) in the 7th century. Since then this place has been one of the famous places of Buddhist training.
The nearest airport from Tenkawa is Kansai International Airport. Take a JR train to Tennoji (天王寺) station, where you can walk to Osaka Abenobashi Station of Kintetsu Railway. Then take a train for Yoshino, get off at Shimoichiguchi Station and catch a local bus.
Cars can be rented at Kansai International Airport.
If you are accessing from Narita International Airport, go to Tokyo Station, take a Shinkansen train to Kyoto, where you can use the Kintetsu line to Shimoichiguchi Station.
Driving is one option. From Koriyama IC (郡山) of Nishi-Meihan Expressway drive Route 24 and Route 169 southbound. At Shimoichiguchi turn right onto Route 309 and drive until you get to Tenkawa.
There is a bus leaving from Kintetsu Shimoichiguchi Station (下市口), which is on the Kintetsu Yoshino Line. You can board an express train (急行) for Yoshino (吉野) at Osaka Abenobashi Station, the Kintetsu station adjacent to JR Tennoji. That train will take you to Shimoichiguchi, from where you can take a bus for about an hour until you reach Tenkawa Mura (天川村)
The information center (天川村総合案内所) is the first place you should drop in on when you reach Tenkawa. They offer guidebooks and information on this area.
Cedar forests, some small mountain rivers, and a few caves.
Daranisuke is a crude drug produced in this area and sold at local drugstores. It is good for gastroenteritis.
When in season, Japanese "mountain vegetables" are a popular and delicious choice. Some places offer fish caught in the mountain rivers, which are bony, but worth trying at least once. The two varieties often seen are iwana (岩魚, charr) and amago (あまご, red-spotted trout).
There are guesthouses and auto campsites in the Tenkawa area.