Iwai Falls in Kagamino: A Cave Like Waterfall with Famous Spring Water

Deep in the mountains of Kagamino in Tomata District, Okayama, within the Hyonosen Ushiroyama Nagisan Quasi National Park, Iwai Falls drops about ten meters with a width of six meters. Its greatest charm is that it is a cave-like waterfall you can walk behind, passing beneath a massive rock face. Watching the curtain of water from the inside is a rare experience indeed.

About one hundred meters downstream a spring known as Iwai gushes forth, and in 1985 it was chosen as one of Japan finest hundred waters. At around ten degrees Celsius, with roughly one hundred seventy tons welling up each day, this soft water is also cherished as water that blesses couples with children.

Highlights

• The rare experience of walking behind the falls. The space, wrapped in the sound of water and cool air, feels mysterious.
• The Iwai spring, chosen among the nation's finest hundred waters. Purifying your hands and taking a sip seems to clear the heart as well.
• The roughly four hundred meter walking path from the parking lot to the falls. The forest trail laid with wood chips settles the mind just by walking it.

Enjoying the Seasons

From spring through summer the fresh greenery dazzles, and the spray and cool air act like a natural air conditioner, making it a popular summer retreat. In autumn the surrounding trees turn color for a fine pairing of foliage and falls. From late December to early April there is snow, and the surrounding area can pile up close to two meters, so visiting in snow-free seasons is safest.

Access and Basic Information

• Location: Nakatsugawa, Kamisaibara, Kagamino, Tomata District, Okayama
• By car: from the Innosho Interchange on the Chugoku Expressway, take Route 179 and then Route 482 for about sixty minutes to reach the Iwai Falls parking lot.
• Parking: free, with space for about twenty-two ordinary cars and three large vehicles. Restrooms are provided.
• From the parking lot it is about ten minutes on foot along the walking path. There are some steep stairs.

Practical Travel Notes

• Best season and time: early summer greenery and autumn foliage are especially beautiful. Summer is ideal for a cool retreat, with chilly air pleasant even at midday.
• Time needed: allow about forty minutes to an hour for the walk, viewing the falls, and a rest at the spring.
• Avoiding crowds: the parking lot fills easily on summer and foliage-season weekends, so an early morning arrival is best. In winter the route is closed, so a visit after the thaw is a sure bet.
• Nearby spots: Okutsu Onsen in Kagamino is a renowned hot spring, and many combine it with the falls.
• Budget: there is no fee to visit. If you wish to take home the spring water, bringing an empty container is handy.

A Quick Tip

The walking path has steep stairs, so wear comfortable shoes. The footing behind the falls is wet and slippery, so proceed carefully. If you wish to take home the spring water, bringing an empty container is handy.

📚 Sources

This article draws on guidance from Kagamino Town and the Kagamino Town Tourism Association about Iwai Falls, materials on the Hyonosen-Ushiroyama-Nagisan Quasi-National Park, information on the Ministry of the Environment's list of one hundred famous waters, and on-site interpretive panels. Statements such as the spring water Iwai being chosen among the hundred famous waters in 1985 and the falls being a waterfall you can walk behind rest on these public materials and on-site panels. Because parking capacity and winter access may change, please confirm current details with official sources such as the Kagamino Town Tourism Association before visiting.

Visitor Checklist

• Estimated time: About forty minutes to one hour combining the walk from the parking lot, viewing the falls, and a rest at the spring.
• What to bring: Wear comfortable shoes as the trail has steep steps and the area behind the falls is wet and slippery; an empty container is handy if you want to take spring water home.
• Getting around: A car is the basic option, about sixty minutes from the Insho interchange; the free parking holds about twenty-two ordinary cars and has restrooms.
• Seasonal note: From late December to early April snow makes the road impassable, so a visit after the thaw is surest.
• Avoiding crowds: On summer and autumn foliage weekends, an early morning arrival is recommended.