Watch your step, Indiana Jones. Exploring the twisting trails of the Shiratani Unsuikyo Gorge requires sure footing as you navigate the rope-like roots of the ancient cedar trees (called yakusugi) that grow, gnarled and twisting, to form a storied forest spanning over 240 hectares. You'll have to catch a ferry (or a flight) to Yakushima island, but the hassle is worth it. These forests hide over 1,900 species and subspecies of flora, including a 7,000-year-old cedar. Routes winding between moss-covered trunks and wet ferns are relatively easy, varying between one and five hours in length, and paths (including a historic Edo-period trail) are well maintained. Watch the animation Princess Mononoke before you visit: it's said Studio Ghibli director Hayao Miyazaki took inspiration from the forest's countless shades of green.

Welcome to the Northern Japan Alps. We'd say these beauties are a little bit different to the European peaks they share a name with. Stretched across Japan's main island of Honshu, the Hida Mountains form the highest range in the country, tickling the sky at 3,000m high and often appearing half-cloaked in shimmering clouds. Lower down, you'll find a thick blanket of bouclé-like forest cloaking the mountain folds; higher up, the bosky terrain gives way to sharp, snow-capped peaks. At less lofty heights, the land swoops into deep gorges, falling beneath clear streams and rock-strewn lava plateaus. Much of the area lies within the Chubu-Sangaku National Park, including Kamikochi, a remote alpine valley famed for its photogenic inhabitants and easy access to day-long foothill walks. Head here to grab a shot of the famous snow monkeys in Japan - the ruddy-faced macaques that hop into hot springs when the weather gets tough - then hit the trail on the Tokugo Pass, a steep 23km-long day hike. These are - hands down - our favourite mountains in Japan.

Despite its outlandish size and overwhelming remoteness, spread across the country's northern extremes, Daisetsuzan, Japan's largest national park, is surprisingly easy to get to. Jump on a bullet train from Tokyo and in just four hours you'll be a quick bus ride away from its two onsen towns, Asahidake and Sounkyo. We'd suggest skipping the much-lauded Grand Traverse route - unless you've brought enough blister plasters for a seven-day excursion. Instead, grab a map and explore the numerous day hikes criss-crossing the otherworldly landscapes. For moon-like high slopes, try the Kurodake Traverse, an eight-hour stomp between gritty hills of orange rock dotted with dramatic craters. Arrive in July and you'll catch endless acres of blousy alpine flora; delay until September for views of the fiery autumn display.

A two-hour drive from Tokyo via Shinkansen, the northernmost prefectures of Japan's largest main island don't get much airtime, but with remote hills, lush forests and bubbling mud pools, it deserves to. You'll want to rent a car to explore as you navigate Iwate's thick forests and Akita's hot springs - and if you're on four wheels, it makes sense to take in the road that's crowned Japan's most beautiful, the Hachimantai Aspite Line. Hiking-wise, though, we're heading to Mount Hachimantai, a 1600m peak. Reserve a spot with a local guide for help in deciphering the native flora and fauna (they'll know what to do if one of the area's Asiatic black bears arrives), and they'll take you to visit the mountain's Dragon Eye, a high-up pond that thaws between May and June in such a way as to resemble an eye of a dragon. Finish your road trip by heading to Lake Towada. Created by some serious seismic activity that began approximately 200,000 years ago, deep, sapphire-blue waters fill Japan's largest crater lake. Nearby, the moss-covered, 14km-long Oirase Mountain Stream trail takes around four hours, and takes in almost 30 waterfalls.

Straddling three prefectures, Japan's oldest national park is awash with… um, water. Lakes, marshes and waterfalls shape its mountain topography, feeding green-swathed forests, carving out 100m-deep canyons and pouring over cliff faces as glittering falls. Head south-west to find Lake Chuzenji and Senjogahara, a storied wetland some 1,400m above sea level that legend suggests was flattened into a battlefield for a war between two mountain gods. Boardwalks circumnavigate this high moor, connecting surrounding hot springs and impressive waterfalls to mountain vistas via trails that take no more than three hours to complete. Arrive in autumn to see the normally verdant moor grass transformed to a furious medley of orange and crimson, with the area's larch trees flaming a brilliant yellow-gold.