If you would like to see natures near city for a day trip,
I recommend these place.
Doesn't need special mountain equipment, just enjoy hiking.
The approach to get there, hundreds of stone statues are standing
in line of both sides.
You will hear the sound of silence,when you walk there in the early morning.
You have a fun in Osaka then take some Zen meditation session at there to relax.
It covers all over the mountain paths around 8 kms,
from the north end to the south of Omine Renzan mountains.
It is also a base of Omine spiritual mountain walk for decipliants.
A path between Yoshino-Omine and Yuya
is called Omine Okukudou and is still used for religeous training.
You can also enjoy hiking.
There is a rope-way and cable car from Kobe(JR Rokkomichi station).
http://www5.ocn.ne.jp/~tenpo45/ (Tenpozan Mountain club in Japanese)