Hiking the Sandstone Canyons: 7 Must-Do Trails in Isalo National Park

Before diving into the trails themselves, let's talk preparation. Isalo's microclimate can surprise even experienced hikers like myself. Despite visiting in fall (April-June), when temperatures are generally pleasant, we encountered both scorching midday heat in exposed canyons and chilly evenings at higher elevations.

First things first: water is non-negotiable. Each person in our group carried at least 3 liters per day in our hydration reservoirs, which proved invaluable during longer hikes. The park's rugged terrain demands proper footwear – I've hiked everything from the Appalachians to the Grand Canyon, and my hiking boots provided the ankle support and traction needed for Isalo's sometimes slippery sandstone surfaces.

Local guides are mandatory in Isalo, and this is one requirement I wholeheartedly endorse. Our guide, Jean, not only kept us on track but shared fascinating insights about the endemic plants that somehow thrive in this harsh environment. His knowledge of the park's geological history rivaled my own and added tremendous educational value for my science-loving teens.

Our Isalo adventure began with the Canyon des Singes, a moderate 4-mile loop trail that served as the perfect introduction to the park's diverse ecosystems. Don't let the name fool you – while you might spot Verreaux's sifaka lemurs (not technically monkeys, as our teens quickly pointed out), the real stars here are the dramatic sandstone walls that tower overhead.

The trail begins in dry savanna before descending into a lush canyon where natural pools reflect the golden cliffs above. The geological contrast is striking – these sandstones were deposited during the Jurassic period when Madagascar was still attached to Africa, and the erosional patterns reveal layers of history like pages in Earth's autobiography.

About halfway through the hike, we reached a series of crystal-clear pools fed by underground springs. My daughter, who inherited my fascination with geology, spent nearly an hour examining how the water had carved smooth bowls into the sandstone. The natural swimming hole here makes a refreshing midday stop, so pack your quick-dry towel – it takes up minimal space in your pack but proves invaluable after a dip in these pristine waters.

The Namaza Circuit leading to the famous Piscine Naturelle quickly became our family favorite. This 7-mile round trip hike offers the perfect balance of challenge and reward, culminating at what I can only describe as nature's perfect swimming pool.

The trail begins with a moderate climb through grasslands where ring-tailed lemurs often forage in the morning hours. We spotted three troops within the first hour! As you continue, the landscape transforms dramatically as you enter a narrow canyon flanked by sculpted sandstone walls. The ecological transition here is fascinating – from dry, exposed grassland to a microclimate supporting lush vegetation including wild orchids and pandanus palms.

After about 3 miles of hiking, you'll hear the Piscine Naturelle before seeing it – the sound of cascading water echoing off canyon walls. The natural pool is fed by a 20-foot waterfall that has carved a perfect swimming hole into the sandstone. The water remains cool year-round, making it an ideal respite from the Madagascar heat.

This trail gets busy by midday, so I recommend using a waterproof dry bag to protect cameras and valuables while swimming. Our teens spent hours exploring the underwater rock formations with their waterproof phone case, capturing underwater videos of the surprisingly diverse aquatic life in these isolated pools.

For photographers and sunset enthusiasts, La Fenêtre trail is an absolute must. Unlike the canyon hikes that require full days, this accessible 1-mile trail leads to a natural rock formation that perfectly frames the setting sun. It's the geological equivalent of a perfect picture frame!

The trail itself is relatively easy, making it ideal for an evening excursion after a more strenuous morning hike. We timed our visit for the golden hour, arriving about an hour before sunset with our camera gear and a light picnic. The natural stone arch – formed by differential erosion of the sandstone – creates a window-like opening that perfectly captures the sun as it descends over the western plains.

As an environmental educator, I was fascinated by how this formation demonstrates the power of wind erosion in arid environments. I explained to my kids how the softer sandstone erodes more quickly than the harder layers, eventually creating these distinctive arches – similar to what we see in Utah's Arches National Park, but with Madagascar's unique geological signature.

For serious photographers, I recommend bringing a lightweight travel tripod to capture the stunning light show as the setting sun transforms the sandstone from gold to fiery orange to deep purple. My lens filters proved invaluable for balancing the extreme contrast between the bright sky and shadowed foreground.

Don't let the unfortunate name deter you – Canyon des Rats (Rat Canyon) offers one of Isalo's most dramatic landscapes and leads to the secluded Piscine Noire (Black Pool). This challenging 9-mile round trip hike requires an early start but rewards with solitude and some of the park's most impressive geological features.

The trail begins with a steep descent into a narrow canyon where the walls close in dramatically, sometimes just a few meters apart. These slot canyon sections reminded me of Arizona's Antelope Canyon, though with a distinctly Malagasy character. The stratified sandstone tells a geological story spanning millions of years – each layer representing ancient sand dunes from when this region was part of a vast desert.

After navigating the narrow canyon (which requires some scrambling over boulders), the trail opens into a broader valley where endemic palm trees create an unexpected oasis. This microclimate supports species found nowhere else on Earth, including several orchid varieties that our guide pointed out.

The trail culminates at Piscine Noire, a deep pool fed by underground springs. Unlike the more popular swimming holes, this one remains in shadow much of the day (hence the name), giving it a mysterious quality. The water appears black due to the depth and mineral content, though it's perfectly clear when examined closely.

This strenuous hike demands proper preparation. My trekking poles proved essential for navigating the uneven terrain, and our water filter allowed us to safely refill our bottles from springs along the route – essential for this full-day excursion.

For experienced hikers seeking the ultimate Isalo experience, the final three trails on my list can be combined into an epic multi-day circuit that showcases the park's most remote and spectacular landscapes. This challenging route connects Canyon des Makis, Piscine Bleue, and the Cascade des Nymphes into a 25-mile journey that requires camping within the park.

Canyon des Makis begins with a moderate climb through savanna before plunging into a deep canyon where troops of ring-tailed lemurs and Verreaux's sifakas are frequently spotted in the early morning. The trail follows an intermittent stream that has carved fascinating erosional features into the sandstone. My geology-loving teens were fascinated by the visible cross-bedding in the canyon walls – evidence of ancient sand dunes from when this region was a vast desert over 200 million years ago.

Piscine Bleue lies about 7 miles from the trailhead and offers what many consider the park's most beautiful swimming hole. The water here contains minerals that give it a striking azure color against the golden sandstone. We spent our first night camping near this natural pool, waking to find lemurs drinking at the water's edge.

Cascade des Nymphes marks the final leg of this epic circuit. This multi-tiered waterfall cascades through a series of natural pools before disappearing underground – a perfect demonstration of the karst topography that makes Isalo's hydrology so unique. The campsite here sits in a natural amphitheater of sandstone, creating unforgettable acoustics as the water tumbles over ancient rock.

For this multi-day adventure, proper gear is essential. Our backpacking tent provided comfortable shelter while adding minimal weight to our packs. I also recommend a quality headlamp for navigating camp after sunset – the canyon gets remarkably dark, but this creates spectacular stargazing opportunities.