Two trails link Park HQ with Kuala Trenggan to the north. Either makes an excellent one day walk, returning by river. Alternatively the two form a good two day round trip, staying at the lodge at Kuala Trenggan or at Bumbun Kumbang overnight.

3a Kuala Trenggan via Gunung Indah

Keen walkers can walk 9 kilometres (5.5 miles) to the lodge and then take a thrilling sampan ride back through the Tembeling Gorge and 7 rapids (Nusa, Dua, Abai, Teras, Dedari, Panjang and Trenggan) along Sungai Tembeling or vice versa. The boat journey takes about 45 minutes and covers about 10 kilometres (6miles). Otters may be seen in these rapids swimming rapidly and catching fish. Hornbills and fish eagles often pass ovehead.

Most visitors take the boat to Kuala Trenggan and back through the rapids. Be prepared to get a little wet, so protect any valuables such as cameras. Lodge accommodation is available at Kuala Trenggan but bookings should be made at the TNR before setting off. The lodge is a lot smaller and quieter than the TNR and there are limited facilities. It sits high above the river and is an ideal location for those who want to escape crowds.  

This first part of the trail to Kuala Trenggan follows the course of the Sungai Tembeling and the canopy walk trail. From here, it involves many steep ascents and descents and is only recommended for those who are physically fit and with good walking shoes. The trip usually takes 4 to 6 hours from Kuala Tahan. It can take longer if side-trips are taken to the look-outs on Gunung Indah (Beautiful Hill) with its interesting vegetation and spectacular views, or to one of several waterfalls along the way. The return trip to Gunung Indah from Kuala Tahan can be done in about 4 hours, but like all trails in the park, there is a lot to see along the way so plan a little extra time.  

The trail beyond the Canopy Walk skirts rock walls and boulders in very steep country, and then climbs sharply up to a T-intersection along a narrow ridge. The righthand path leads down to the Sungai Tembeling and a deep pool called Lubuk Udang (Prawn Pool). From here a branch trail goes on to Kuala Trenggan.

Back on the ridge, the left hand path is a steep trail leading up the Gunung Indah ridge to the base of a narrow outcrop of glass-like, quartzite rock. Quartzite is a metamorphic rock tat is extremely hard and weathers more slowly than the surrounding rock and, as a result, stands out. Walkers should exercise caution on the steep climb to the look-out.

At the look-out the environment changes dramatically from lowland rainforest to exposed cliffs with stunted vegetation growing on thin soils. Scientists still have much to learn about this unique environment. The soils are poor and infertile due to the slow erosion rates of the parent rock. Another problem for plant survivial here is that of drought. This may sound odd in the middle of a rainforest, but a few days without rain in a rainforest can severly affect plants sensitive to moisture retention.

The vegetation on Gunung Indah is unique so all visitors here need to be very careful about conserving the species that inhibit the area. One interesting plant is the red, papery-barked tree that belongs to the Eugenia genus.

The upper and lower look-outs overlook Lubok Udang and the roaring rapids, Jeram Nusa, about 120 metres (400ft) above. The trail to the summit of Gunung Indah is a dead-end and walkers have to retrace their steps to the base of the mountain.

There are several options for visiting Gunung Indah. Visitors can walk part of the way and travel by boat for the rest. For example, boats travelling up the Sungai Tembeling can drop off or pick up passengers at Lubuk Udang. This means visitors can walk to the mountain and then catch a boat out or vice versa.

Beyond Gunung Indah the trail enters more rugged country, and some sections may be difficult after rain. While the trail is well above the river in many places, there are lower sections from which it is possible to side-track down to the water’s edge.

At the second permanent stream crossed after the Gunung Indah ridge there is a large rock overhang beside a narrow, deep pool. From the trail and up the stream bed there is a small waterfall some 15 minutes wade upstream.

One kilometre (1/2 mile) further along the trail reaches Sungai Trenggan. This is crossed by means of a raft on a fixed rope. It is safest for only person to cross at a time. Just 150 metres (170yards) more along the trail and there is a junction with Kuala Trenggan 5 minutes walk to the right and Bumbun Kumbang about 40 minutes walk to the left.

Kuala Trenggan is in a beautiful location high above Sungai Tembeling. There are 10 wooden chalets, each sleeping a few people. There is also a simple restaurant and the facilities are quite comfortable for those looking for a peaceful rainforest retreat. An adjoining campsite offers a cheaper alternative for backpackers.