These notes follow the trail in a counterclockwise direction, commencing from the Matang Wildlife Centre camping ground, located on the Sungai (river) Rayu's left bank, downstream from the concrete road bridge at the park entrance.
Follow the trail markers left (away from the river), crossing a small bridge over a creek and up a short rise, immediately after leaving the camp ground. The trail is marked by white paint on trees. This initial relatively flat section passes through kerangas forest, dotted with some pretty licuala palms. About 10 minutes from the camp ground, look out for abundant clusters of globular pitcher plants on the ground, mainly to the left of the trail. These are Nepenthes ampullaria, used by some indigenous groups as containers in which to cook rice. The "pitchers" are in fact specially adapted leaves, which trap and slowly digest insects, providing a "nutritional supplement" to the plants, which typically grow in poor soils.
Over the following 15 minutes, the trail crosses a small creek, through open forest with stilt-root trees, pandanus plants and fan palms, to another tiny creek fringed (on the right of the trail) with spectacular large pandanus. There are more than 700 species of pandanus plants, commonly called screw-pine because the elongated, pleated leaves spiral outwards from the stem. A very commonly used species throughout South East Asia is Pandanus odoratus; juice extracted from the leaves is bright green and fragrant. It is an essential ingredient in South East Asian cooking - almost all sweets will be flavoured with pandan (and sometimes be a disturbing shade of green). It is South East Asia's equivalent to vanilla.
Beyond this there's more swampy creek crossings on single planks, and then the forest becomes drier. The forest along this part of the trail is more established and there are some large dipterocarp trees growing here. The turn-off to the Sungai Buluh Trail branches off to the right of the trail, about 25 minutes walk from the camp ground.
From the Sungai Buluh turn-off, the path continues downwards across another trickling creek, after which the trail becomes a 15 minute (or so) sweaty, zig-zagging climb up a steep slope. There's some thick stands of plants with beautiful large paddle shaped leaves on fine straight stalks - these are daun lung besai (Phacelophrynium maximum) and the leaves are used by Iban as plates, food wrappers and for roofing. Some large dipterocarp trees are also dottedthroughout this area. Towards the top of the slope, pale, smooth-trunked selunsor trees (Tristania sumatrana) are easily recognisable by the great sheets of bark at their bases. These trees resemble Australian gums, to which they are related, and are a tangible link to the days of Gondwanaland, when Australia and Borneo were joined. Near the top of the climb, a wooden amphitheatre has been built. It's a good place to catch your breath. There's another short uphill stretch before reaching the ridgeline.
From the ridge top, the trail passes through dipterocarp forest into a saddle, then continues along the dry ridge line. There are some views to the right into and across the Sungai Buluh valley. About 10 minutes from the wooden amphitheatre, the trail veers downhill, where there are several damar-producing trees. Damar is the local name for a fragrant tree tree resin, usually from meranti (Shorea sp), a type of dipterocarp tree. The uses for damar in the past included as incense, makeshift candles and for waterproofing boats. It is still used commercially for wood varnish. One of these trees is on the left hand side of the trail, not far from the start of the descent. It is very tall and straight, with horizontally ridged pale bark and viscous, clear brown resin oozing from a wound at the base.
As the trail descends, you may get some glimpses of the green Sungai Rayu valley in front. With the loss of altitude, the surrounding vegetation becomes denser and moister, and you'll eventually hear the sound of running water in front.
At the bottom, the trail crosses several small creeks which have an amazing diversity of palm species, most of which had some traditional uses. The very tall, thin palms with viciously spiny stems are nibong palms (Oncosperma horridum). The trunks of these were used by the Iban in by-gone days to defend their longhouses; and the cabbage (shoot) is edible, but tricky to collect (you have to cut down the whole tree). Beccari enjoyed munching on some of these during his stay at Matang.Various types of rattans (climbing palms) are also common throughout this part of the trail - some of these have edible fruit, and have traditionally had many craft uses - weaving baskets, mats, cane furniture etc. Two very large varieties of fan palm (Licuala sp) are also found in this area.
The trail through this area is quite swampy. Some trees here have aerial roots, an adaptation to poorly drained soil which is similarly seen with some mangrove trees. There are several more ups and downs as the trail passes through small creek gullies, crossing the creeks using single planks or logs.
The trail then levels out, reaching a junction with the turn-off to the Sungai Rayu Waterfall (1.6km onwards) and the View Point Trail. It takes about 35 minutes to get to this junction from the wooden amphitheatre. Here, the trail approaches the Sungai Rayu, where you many notice some graceful and striking trees with bright orange trunks lining the riverbank. These are selunsor merah trees (Tristania beccarii), a close relative of the white barked selunsor trees seen previously on the slopes of the trail.
The trail continues with the Sungai Rayu to the right, then veers briefly away from it, crossing a small creek with more nibong palms and lots of fringing pandan plants. After returning to the River, it is a gentle walk along a sandy / muddy path along to the turnoff to the Rayu Trail (to Kubah HQ), at a suspension bridge. A little further, close to the HQ, the riverbank has been developed with picnic facilities and public amenities. The shallow, wide stretches of the river provide an ideal place to swim and cool off. From the previous junction (the Sungai Rayu Waterfall and View Point) back to the Matang HQ takes approximately 20 minutes.