Where is Minamiaiki Dam located and how do I get there?

Minamiaiki Dam is located in Minamiaiki Village, Minamisaku District, Nagano Prefecture, Japan. You can reach the dam by car via Route 141 or take the JR Koumi Line to Koumi Station and then drive approximately 15 minutes to the dam site.

What are the best activities and attractions at Minamiaiki Dam?

Minamiaiki Dam offers excellent fishing opportunities for trout, scenic hiking trails around the reservoir, photography spots with mountain views, and seasonal activities like cherry blossom viewing in spring and autumn foliage tours. The dam also provides beautiful panoramic views of the surrounding Japanese Alps.

When is the best time to visit Minamiaiki Dam?

The best time to visit Minamiaiki Dam is during spring (April-May) for cherry blossoms, summer (June-August) for fishing and hiking, and autumn (October-November) for stunning fall foliage. Each season offers unique scenic beauty and different outdoor activities for visitors.

Are there accommodations and facilities near Minamiaiki Dam?

Yes, there are several accommodations near Minamiaiki Dam including traditional ryokans, hot spring resorts, and camping facilities. The area also features restaurants serving local Nagano cuisine, visitor centers, parking areas, and restroom facilities for tourists.

What should I know about fishing at Minamiaiki Dam?

Fishing at Minamiaiki Dam requires a valid fishing license and offers excellent trout fishing including rainbow trout and brown trout. The best fishing seasons are spring through autumn, with early morning and evening being the most productive times. Local bait shops provide equipment and fishing permits.

Nagano

Minamiaiki Dam

4.3 (304)Tourist AttractionPoint Of InterestEstablishment

Last updated Sep 18, 2026

The Minamiaiki Dam is a concrete gravity dam located on the Minamiaiki River in Minamiaiki Village, Nagano Prefecture, Japan. Completed in 1969, the dam was constructed primarily for flood control and hydroelectric power generation. Standing at 70 meters in height with a crest length of 260 meters, it creates the Minamiaiki Reservoir, which has become an integral part of the region's water management infrastructure. The dam was built by the Japan Water Agency as part of broader development efforts in the Chikuma River system.

The surrounding area offers visitors a tranquil escape into the Japanese Alps, with the reservoir providing scenic views throughout the changing seasons. The dam site is particularly attractive during autumn when the mountainous landscape displays vibrant foliage reflected in the calm reservoir waters. Cherry blossoms in spring also draw visitors to the area. The region around Minamiaiki Village is known for its highland climate and pristine natural environment, making it a pleasant destination for those seeking mountain scenery and rural Japanese landscapes.

Visitors can view the dam structure from observation areas and walk across the dam crest, which offers panoramic views of both the reservoir and the valley below. The surrounding area features walking trails and parks suitable for picnicking and nature observation. The reservoir itself is not typically used for water sports or fishing, maintaining its focus as an infrastructure and scenic viewing location. Photography enthusiasts appreciate the dramatic engineering against the mountain backdrop.

Access to Minamiaiki Dam requires private transportation as public transit options are limited. The dam is approximately 20 kilometers from Koumi Station on the JR Koumi Line, taking roughly 30 minutes by car. From Saku city, the drive takes about 40 minutes via Route 299. Parking facilities are available near the dam site. There is no admission fee to view the dam or access the observation areas, making it a cost-free attraction for travelers exploring the highland regions of Nagano Prefecture.

Website

www.minamiaiki.jp

Overview

Address

6101-2, Minamiaiki, Minamisaku District, Nagano 384-1211, Japan

Website

www.minamiaiki.jp

Traveler reviews

Excellent view. Worth for all the way driving.

Ganesan M

Sep 23, 2022

I visited after seeing it in mono. Looking at it from the car park next to the dam, I realised it was a rockfill dam. To be honest, when I went to the top of the dam and looked down, I felt a bit underwhelmed. The gentle slope made it seem like it would be easy to climb up from below, but it lacked the terrifying impact of the huge drop that comes with a typical gravity concrete dam. After that, I crossed over the dam and at the other end checked the discharge channel in case of overflow. Of course, with a stone dam, there is a risk of it bursting if water overflows the top of the embankment. After being impressed by all the ingenuity that had gone into it, I moved to Uzumaku Hiroba below the dam. I headed towards the tunnel with a door, feeling a little unsure if it was okay to go through, but was stunned to see the overflow channel that looked like a giant roller coaster. What a complete reversal of my impression of it being tame. Even Lupin the Third would not survive if he ran down this slope. Is it a parabola that curves from the gentle slope to the basin? The sight of it piercing the river is breathtaking. The stillness of the beautiful, white, gentle slope of the dam body. The movement of the overflow channel, which forms an overwhelmingly powerful curve! Minamiaiki Dam wouldn't be complete without these two. If you think you've only ever visited Minamiaiki Dam to see it from the top, you're missing out on something. A return visit is a must.

三間裕樹

Jul 28, 2025

Visited in April 2025. This is the highest dam in Japan. The route follows the Minamiaiki River, winding through the final stretch to the finish line. There was a marble monument in the plaza. It's a road I'd rather avoid at night. The crisp air, the magnificent dam lake, the lingering snow on the Yatsugatake Mountains in the distance, and the whitish rocky dam body are all incredibly beautiful. It feels like you have nature all to yourself. Contrails were appearing and disappearing in the sky. If you have time, a walk around the dam lake is also a good idea. There's nothing there except toilets, so be prepared. I received my dam card at the Minamiaiki Onsen Takimi-no-Yu hot spring along the way. (Photo required)

960 im

Apr 21, 2025

This rockfill dam was made using limestone, and on sunny days the white limestone looks very beautiful. Also, if you visit during the autumn foliage season, the contrast between the white limestone and the autumn leaves is very beautiful. However, please be careful as there are falling rocks on the road leading up to here. (The photo was taken in November 2021.)

33 mac

Jul 29, 2025

I visited again in May 2026, before the rainy season, after an 11-month absence. Tonight was cloudless, and the starry sky was beautiful. I visited again on the night of June 28th, 2025. I came to photograph the starry sky, but it was cloudy. The clouds started to clear around midnight. It's an hour's drive from the highway, there are many falling rocks, no vending machines, no internet connection, lots of deer, probably bears too, the toilets are clean, the starry sky is amazing, and it's very quiet because there are few people. Despite all that, I love this place. I visited in October 2021 to photograph the Draconid meteor shower. I've been here many times, but this was my first time this year! I bravely walked around the dam lake at night—please don't let any bears come out! It's dangerous to go at night.