The two most popular ways to climb Gunung Rinjani are a five-day trek (described below) that starts at Senaru and finishes at Sembalun Lawang, or a strenuous three-day dash from Senaru to the crater rim and back. A guide is essential from the hot springs to Sembalun Lawang, as the path is indistinct. This trek is outlined on the Gunung Rinjani Map. Another good map is the one from the Rinjani Trek Centre (RTC) – it’s large, in colour, glossy and easy to understand.
It’s often not possible to climb Rinjani during the wet season (November to March), particularly after heavy rainfall when the trail around the lake is very dangerous due to potential landslides and rockslides.
Day One: Senaru Pos I to Pos III (five to six hours)
At the southern end of Senaru is the Rinjani Trek Centre (Pos I, 601m), where you register and pay the park fee. Just beyond the post, the trail forks – continue straight ahead on the right fork. The trail climbs steadily through scrubby farmland for about half an hour to the sign at the entrance to Gunung Rinjani National Park. The wide trail climbs for another 2½ hours until you reach Pos II (1500m), where there’s a shelter. Water can be found 100m down the slopes from the trail, but it should be treated or boiled.
Another 1½ hours’ steady walk uphill brings you to Pos III (2000m), where there are two shelters in disrepair. Water is 100m off the trail to the right, but it sometimes evaporates in the dry season. Pos III is usually the place to camp at the end of the first day.
Day Two: Pos III to Danau Segara Anak & Aiq Kalak (four hours)
From Pos III, it takes about 1½ hours to reach the rim, Pelawangan I, at an altitude of 2641m. Set off very early for the stunning sunrise. It’s possible to camp at Pelawangan I, but there are drawbacks: level sites are limited, there’s no water and it can be very blustery.
It takes about two hours to descend to Danau Segara Anak and around to the hot springs, Aiq Kalak. The first hour is a very steep descent and involves low-grade rock-climbing in parts. From the bottom of the crater wall it’s an easy 30-minute walk across undulating terrain around the lake’s edge. There are several places to camp, but most locals prefer to be near the hot springs to soak their weary bodies and recuperate. There are also some caves nearby which are interesting, but are not adequate shelter. The nicest campsites are at the lake’s edge, and fresh water can be gathered from a spring near the hot springs. Some hikers spend two nights or even more at the lake, but most who are returning to Senaru from here head back the next day. The climb back up the rim is certainly taxing – allow at least three hours and you’ll have to start early to make it back to Senaru in one day. Allow five hours from the rim down to Senaru. Instead of retracing your steps, the best option is to complete the Rinjani trek by continuing to Sembalun Lawang and arranging transport back to Senaru.
Day Three: Aiq Kalak to Pelawangan II (three to four hours)
The trail starts beside the last shelter at the hot springs and heads away from the lake for about 100m before veering right. It then traverses the northern slope of the crater, and it’s an easy one-hour walk along the grassy slopes before you hit a steep, unforgiving rise; from the lake it takes about three hours to reach the crater rim (2639m). At the rim, a sign points the way back to Danau Segara Anak. Water can be found down the slope near the sign. The trail forks here – go straight on to Lawang or continue along the rim to the campsite of Pelawangan II (2700m). It’s only about 10 minutes more to the campsite, which is located on a bare ridge.
Day Four: Pelawangan II to Rinjani Summit (five to six hours return)
Gunung Rinjani stretches in an arc above the campsite at Pelawangan II and looks deceptively close. Start the climb at 3am in order to reach the summit in time for the sunrise and before the clouds roll in.
It takes about 45 minutes to clamber up a steep, slippery and indistinct trail to the ridge that leads to Rinjani. Once on the ridge it’s a relatively easy walk uphill. After about an hour heading towards what looks like the peak, the real summit of Rinjani (3726m) looms behind, and as you gain altitude you’ll see it towering above you.
The trail then gets steeper and steeper. About 350m before the summit, the scree is composed of loose, fist-sized rocks – it’s easier to get along by scrambling on all fours. This section can take about an hour. The views from the top are truly magnificent on a clear day. The descent is much easier, but again, take it easy on the scree. In total it takes three hours or more to reach the summit, and two to get back down.
Day Four/Five: Pelawangan II to Sembalun Lawang (five to six hours)
After negotiating the peak, it’s still possible to reach Lawang the same day. After a two-hour descent, it’s a long and hot three-hour walk to the village. Head off early to avoid as much of the heat of the day as possible and make sure you’ve brought along plenty of water. From the campsite, head back along the ridge-crest trail. A couple of hundred metres past the turn-off to Danau Segara Anak, there is a signposted right turn leading down a subsidiary ridge to Pada Balong and Sembalun Lawang. Once on the trail, it’s easy to follow and takes around two hours to reach the bottom.
At the bottom of the ridge (where you’ll find Pada Balong shelter; 1800m) the trail levels out and crosses undulating to flat grassland all the way to Sembalun Lawang. After about an hour you’ll hit the Tengengean shelter (1500m); it’s then another 30 minutes to Pemantuan shelter (1300m). Early in the season, long grass obscures the trail until about 30 minutes beyond Pemantuan. The trail crosses many bridges; at the final bridge, just before it climbs uphill to a lone tree, the trail seems to fork; take the right fork and climb the rise. From here, the trail follows the flank of Rinjani before swinging around to Sembalun Lawang at the end. A guide is essential for this part of the trip.
Variations on trekking Rinjani
There are a few possible variations to the route to the top of Gunung Rinjani described above. They’re outlined here:
Compress the last two days into one (racking up a hefty 10 to 11 hours on the trail). On the plus side, it’s downhill all the way after the hard climb to the summit.
Retrace your steps to Senaru after climbing to the summit, making a five-day circuit that includes another night at the hot springs.
Another popular route, because the trail is well defined and (if you’re experienced) can be trekked with only a porter, is a three-day trek from Senaru to the hot springs and back. The first night is spent at Pos III and the second at the hot springs. The return to Senaru on the final day takes eight to nine hours.
For (almost) instant gratification (if you travel light and climb fast) you can reach the crater rim from Senaru in about six hours. You’ll gain an altitude of approximately 2040m in 10km. Armed with a torch (flashlight), some moonlight and a guide, set off at midnight to arrive for sunrise. The return takes about five hours.
If you reach Pelawangan I early in the day, consider taking a side trip along the crater rim, following it around to the east for about 3km to Gunung Senkereang (2919m). This point overlooks the gap in the rim where the stream that comes from the hot springs flows out of the crater and northeast towards the sea. It’s not an easy walk, however, and the track is narrow and very exposed in places – if you do decide to give it a go, allow around two hours to get there and back.
Start trekking from Sembalun Lawang (a guide is essential), from where it takes six or seven hours to get to Pelawangan II. This is a shorter walk to the rim than from Senaru, with only a three-hour trek up the ridge.