Mount Rinjani Summit Trek

Ascent from Sembalun Highly recommended for seasoned trekkers and adventure-driven hikers seeking a challenging high-altitude expedition.

The first hour of the trek unfolds gently across rolling hills, winding through lush vegetable fields and traditional farmland. This is by far the easiest stretch of the entire journey, a soft introduction before the real adventure begins.

Once you leave this cultivated landscape behind and cross a small stream, the trail takes on a deeper story. It follows the remnants of an ambitious 30-year-old project, initiated during the era of President Suharto, when a road was being carved from Sembalun Lawang to the crater lake of Rinjani. Fortunately, due to political upheaval and lack of funding, the project was abandoned. Nature has since reclaimed the land, slowly but surely. Today, lucky trekkers benefit from a series of scenic bridges spanning ancient lava flows, turning this section into a surprisingly enjoyable and unique hiking experience.

At around 1,220 meters, you briefly enter a shaded forest corridor, a welcome break, but beyond that, shade becomes a rare luxury. The second hour continues across undulating hills and open grasslands. Post 1 (Pemantauan), at 1,428 meters, offers a shelter, but most trekkers push on to Post 2 (Tengengean, 1,513 meters), often stopping on one of the bridges for a scenic lunch break.

Post 3, Pada Balong (1,772 meters), marks a turning point, this is where things start to get serious. The trail steepens, the terrain toughens, and the real climb begins.

Over the next three hours, it’s a relentless push uphill. You’ll constantly have your eyes fixed on what looks like the summit, only to discover, time and time again, that it’s just another ridge. A true mental challenge. But once you finally conquer the last ridge, the reward is breathtaking.

To your left rises the mighty Rinjani summit, and straight ahead, 600 meters below, lies the stunning Segara Anak crater lake (“Child of the Sea”), offering one of the most spectacular views in all of Indonesia.

The trail then hugs the crater rim for about 20 minutes, leading you to your final destination for the day: Sembalun Rim (Plawangan Dua, 2,658 meters), where camp is set for the night. The rim provides ample, comfortable space for multiple campsites. A short detour leads to a rocky outcrop where crystal-clear spring water flows, the perfect spot to refresh yourself in icy mountain water and refill your bottles.

As with any volcanic ascent, timing is everything. During the dry season, nights are typically crystal clear, making a half-moon period ideal for summit attempts. Around 3 a.m., the moon sits high enough to illuminate the trail, often eliminating the need for a headlamp.

The first 350 meters from camp are steep but manageable, following a firm trail through high-altitude vegetation. Soon after, the terrain shifts dramatically into loose volcanic scree at around 3,000 meters. The initial climb leads to the crater ridge (2,969 meters), where moonlit views of Rinjani and the surrounding crater are simply unforgettable.

The next 400 meters of elevation gain are deceptively pleasant, the trail remains relatively compact, though steadily steeper. However, the altitude begins to take its toll, slowing your pace and testing your endurance. As you climb higher, the horizon gradually brightens, hinting at the approaching sunrise.

With every step, the summit feels closer, yet at least an hour of effort and 300 vertical meters still stand between you and the top. For anyone thinking Rinjani is an easy hike, think again. The final 300 meters are pure volcanic climbing at its rawest.

The last stretch is brutally steep, with deep, loose sand offering almost no grip. It’s a constant battle: one step forward, half a step back, for what feels like an endless hour. At this altitude, you’ll find yourself stopping every 10 meters just to catch your breath.

By now, daylight transforms the entire landscape. The volcanic complex reveals itself in full grandeur. The final meters become a race against the rising sun. A few more steps, a rock for shelter from the wind, another ridge, one last turn, and finally, you reach the summit of Indonesia’s second-highest volcano.

The first hour after sunrise is pure magic. Colors shift minute by minute, creating endless opportunities for breathtaking photos. At this altitude, proper gear is essential, warm layers, a spare shirt, and a fleece jacket to shield you from the often harsh, cold trade winds. Reaching the summit before sunrise without proper protection is strongly discouraged.

The descent follows the same route back to camp and takes less than half the time of the ascent. It’s tempting to slide down the scree, but don’t forget to pause and take in the incredible scenery one last time.

The next stage down to the lake is less physically demanding but more technical, with slippery terrain. The first hour is steep and slow, but eventually the trail eases, winding through alpine meadows and old lava flows reclaimed by vegetation. Gradually, the lake reveals itself.

Dramatic volcanic walls surround and protect Segara Anak, while the eastern face of Rinjani plunges nearly 1,700 meters straight down into the crater lake, an awe-inspiring sight.

At 2,020 meters, the lake area isn’t always pristine. Large groups of pilgrims often use it as a resting point, sometimes leaving behind plastic and waste. However, one of the main highlights here is the nearby hot springs (Aik Kalak), just a 10-minute walk away.

To reach them, follow the lake’s outlet, cross the stream twice, and descend a steep hill for about 200 meters. Natural pools have been formed to capture the hot spring water, creating bathing spots, though some are algae-filled. The higher pools are often too hot and less clean, but the lower basin, fed by small waterfalls, offers the perfect temperature and a much more enjoyable experience.

For those seeking an extra adventure, it’s possible to climb Mount Barujari (also known as Gunung Baru), the active cone rising from the lake’s center. Following the eastern shore leads to its base. The round trip takes at least four hours and may require an additional night at the lake. Note that access may be restricted during periods of volcanic activity.

At the base, you’ll find more hot springs feeding into a small bay, an incredible place to bathe or even camp overnight. From here, it takes about an hour to reach the summit of this still-growing, smoking volcano (2,363 meters).

On the final day, from the hot springs, head north via Goa Susu (“Milk Cave”, 1,885 meters) toward Torean, over 10 kilometers away, where your vehicle awaits to take you back to your hotel.

Technical overview (topographic reference):

• Trekking time: 4 to 8 hours per day
• Total elevation gain/loss: approx. 3,150 meters