This article is part of our collection of cycling routes and reports for Fukuoka and Kyushu. Explore more rides on our index page—and get out and discover Kyushu
Text and photos by: Tim Muzik / Follow on Strava
Today we’re heading out for a loop around the Aso Caldera. Japan’s largest active volcano, and one of the biggest calderas in the world, is already famous for its dramatic landscapes and distinct natural beauty. But for cyclists it’s also a world-class riding destination. With quiet roads, endless climbs, and surreal, otherworldly views in every direction, this area ranks high among the best places to ride a bike on the planet.
Route Overview
Route Highlights: Milk Road, Kabutoiwa Scenic Overlook, Aso Skyline Observatory, Daikanbo Lookout, Hakoishi Pass Observatory, Minami Aso, Kumamoto Earthquake Museum, Shin Aso-ohashi Bridge Lookout Point
Length: 84 km
Climbing: 1540 m
GPX File
Formed by a series of massive eruptions over 90,000 years ago, the Aso Caldera spans roughly 25 kilometers north to south and 18 kilometers east to west, surrounding five main peaks: Mt. Neko, Mt. Taka, Mt. Kishima, Mt. Eboshi, and the still-active Mt. Nakadake. This 84 km route around the edge of the caldera is, in my opinion, the best ride for cyclists visiting Aso for the first time, offering panoramic lookouts over the valley and the smoking peaks.
Rachel and I were fortunate to spend a week based in Aso cycling and hiking in May 2025. After riding hundreds of kilometers and climbing thousands of meters, this route stood out as our favorite.
The Northwest Ridge
To start the caldera loop, you first need to get on top of the outer rim. For us, it began with the climb out of Akamizu on Prefectural Route 23, which connects to the aptly named Milk Road. The ride up Route 23 is packed with switchbacks and offers some of the best views of the entire loop. Once you’re out of the caldera and onto the Milk Road on the Northwest rim, the climbing continues, winding its way upward for about 500 meters of elevation gain.
Beautiful, green, treeless hills line the route, and constant views of the Aso peaks help make the big climb feel easier. The first natural break comes at the Kabutoiwa Lookout, which also happens to have a small bakery and coffee shop just across the road. It’s worth stopping here as there really isn’t a wealth of food and drink options for the next chunk of the ride. If new to this area, this is a great place to get a feel for the size and shape of the caldera you will be cycling around, as the lookout provides a great vantage point.
The next 20 kilometers are completely wild, with caldera and volcano views to your right and rolling farm fields and the distant peaks of Kuju creeping closer. The Daikanbo Lookout is another worthy stop, though Rachel and I chose to roll past, it turns out that during Golden Week, this area is understandably popular with motorized two-wheel vehicles and we didn’t feel like facing the crowds.
The Quiet Farming Lanes of the Milk Road
In order to stay true to the day’s mission and stick to the crater rim whenever possible, the route veers off the main highway and hops onto a much quieter, less-trafficked section of the Milk Road. Within seconds of turning onto this road, a large deer darted across our path, and we didn’t see another living thing, human or animal, for the next 7 km.
After this quiet stretch crosses National Route 57, the route turns onto an even smaller, rarely used, and at times almost eerily silent farm road that runs between Route 57 and Route 265. This 6.5 km section is easily one of the most interesting and beautiful roads we’ve ever ridden. Don’t let the slightly rough surface or total lack of people put you off. One added bonus: it sticks to the caldera rim and saves you from a 300+ meter descent and climb (skipping climbs here is acceptable as it’s more true to the caldera’s edge).
Minami Aso
Swinging around the easternmost edge of this route, you finally must break from the goal of clinging to the top of the caldera, as no direct roads exist, at least not for road bike tires. Here you must start shedding some of that hard-earned elevation and descend to the caldera floor in Minami Aso. Here you can stay toward the outside edge and roll through Takamori, or stick to quiet roads and make a right onto the Minami Aso Agricultural Road.
Along this route, there are some wild views of the back of Neko Dake and the unique homes of lucky Minami Aso citizens who reside here. This section feels different from the rest of the route thus far and is part of what makes this such a diverse and world-class route.
Remnants of the 2016 Quake
After 13 km of empty, beautiful farm roads, the ride meets up with National Route 325 and an extremely welcome sight: the first and only convenience stores of the ride so far. A wood-decorated Lawson and a shining 7-Eleven offer two choices for the now starving and tired cyclist.
After recharging with food and caffeine, it’s best to descend away from the 325 onto some of the more peaceful farm roads that wind through the caldera valley. If heading back toward Kumamoto, you will need to choose between making the 400 m climb up to the Tawara View Lookout or taking the flatter option over the Shin Aso Bridge toward Tateno Station.
If you want to complete the full loop (a desirable look on Strava) there is a wealth of interesting sites that pay homage to the earthquake that hit this region in 2016 including the Kumamoto Earthquake Memorial Museum, and Sugaruga Falls Lookout. For One Piece fans, the museum also houses one of the bronze One Piece characters designed to help bring tourism back following the devastating quake.
Whether you are rolling back to Kumamoto or staying over in the Aso area this is a route that will have you thinking about planning your next trip soon.
This article is part of our collection of cycling routes and reports for Fukuoka and Kyushu. Explore more rides on our index page—and get out and discover Kyushu
