There are 2 possible paths to reach the small sanctuary on 5th level, the fast but a lot less interesting way and the way via the footbridges that go up gradually (at the first branch with 2 stairs, choose right staircase). The views over the valley are superb and you will also see a sanctuary on a peak. The last of the 7 levels is normally now closed to the public as it is infested with ... snakes. Count 2 hours to go up and down and enjoy the mountain.
Wat Phu Tok is a temple and when you visit a temple in Thailand there are some rules to know and follow :