Entry into the valley is allowed only from 8AM to 1PM. The Forest Department deliberately does not allow going to the valley early in the morning to minimize disturbance to the animals. Every vehicle will have a free guide. The vehicle will move slowly all the 23 km and they will stop a few times on the way for five minute photo sessions. Animal sightings are quite rare and the view from the watch tower at the end is quite spectacular. Only 12 adults are allowed into the watch tower at a time. But a lot of Indians ignore this warning and get into it creating a dangerous situation to the fragile structure. This point is 1,050 meters above sea level. You can trek down to Kunthi river and see the hanging bridge. One hour is allowed in this place.
Apart from that, the trip can disappoint you if you are not a tree bum. Thick vegetation of the silent valley evergreen forest is the only attraction. The road is unpaved and the terrain very bumpy. They take a total of five hours for the trip. If you forget to take drinking water, you are lucky, very tasty mineral water is available free behind the parking space at the watch tower. If you are carrying a bottle of commercial 'mineral water', you can empty the bottle and fill it to the brim with this pristine water.
The signboards of the government on the main road outside can mislead you because distance to the park is shown including the 22 km inside the park. So every time you see 'Silent Valley National Park', you have to reduce 22 km. Similarly the distance to 'Attappadi' means that so many km more to finish Attappadi region and not so many km to reach Attappadi. You cannot reach Attappadi because it is not a place but a region. The entire stretch between Mukkali and Agali is called 'Attappadi' and Agali town is also sometimes referred to as Attappadi.