ABOUT
The formation of Kiyotsu Gorge
16 million years ago,
the eruption of a submarine volcano covered the ocean floor in a thick layer of volcanic ash.
Via a chemical transformation,
this ash turned green in color, forming a type of rock known as green tuff.
5 million years ago,
magma flooded the space under this layer of green tuff, cooling and hardening to create
porphyritic rock.
As it cooled, it contracted, resulting in structures called columnar jointing.
Later, during a period of significant surface layer activity, the seabed rose and became dry land.
It continued to be forced upward, forming mountains.
At the same time, a river (the Kiyotsu River) wore into the
mountains, forming a valley.
As the mountains were worn away,
the porphyritic columnar jointing underground was revealed at the bottom of the valley.
The valley grew even deep, resulting in what we know as Kiyotsu Gorge today.
About columnar jointing
Columnar jointing consists of four- to six-sided natural rock pillars formed when magma cools and hardens.
The rocky walls of Kiyotsu Gorge are made up of columnar joints jumbled together (like bundles of hexagonal pencils).
As
they are not made up of single, large slabs of stone, while the rock itself is hard, the walls are fragile and can
collapse relatively easily.
Similar columnar jointing can also be seen in Akiyamago in adjoining Tsunan Town.
On Mt. Yamabushi, also in Tsunan Town, you can see horizontal columnar jointing.
Tuff・・・Tuff forms when volcanic ash solidifies into rock.
Porphyrite・・・Porphyritic rock is a type of volcanic rock formed when magma cools and hardens. Andesite and basalt are formed via similar processes.
The history of Kiyotsu Gorge
The presence of hot springs in the area was already known some 300 years ago.
Starting from around that time, there was talk of developing the hot springs for baths,
but due to the terrain and a large number of other challenges, no progress was made on this front for many years.
Finally, in 1862, a hot spring spa was built by local residents, which still exists to this day.
In 1941, the gorge was designated a National Place of Scenic Beauty and Natural Monument due to its beauty and magnificent columnar jointing.
In 1949, the gorge was designated a part of Joshin'etsu-kogen National Park,
after which time it became a renowned sightseeing destination.
A hot spring district was also built in the area.
In February 1984, a large snow avalanche directly struck a section of the hot spring district, killing and wounding
several people.
The current Kiyotsukan inn was rebuilt after that time.
Four seasons of Kiyotsu Gorge
Spring
Early May – late June The best time for fresh verdure and river beauty
Snowmelt fills the river and, with the onset of the late spring, new greenery bursts forth all at once, instantaneously
filling the previously drab landscape with color.
Lingering patches of hardened snow formed by the repeated accumulations of avalanches during the winter can be seen here
and there on the gorge bottom.
Patches of snow also hang over portions of the river, but the river continues to flow unabated underneath and never
becomes blocked during this time.
The snows melt away on the ground, sometimes leaving natural bridges of snow over the river hollowed out by the water
flowing underneath.
If you are very lucky, you just might get to see a mass of this snow collapsing into the river with a loud splash.
Via avalanches and winds, the surfaces of any lingering patches of snow accumulates dried leaves and dirt from the
surrounding forest, turning them a brown color.
Snow can linger here up to around June.
The first new leaves begin appearing from about the end of April. The colors of the leaves differ subtly depending on
the species, resulting in beautiful scenery that is a match for the area’s spectacular fall foliage.
Meanwhile, on the banks of the river where the snows have only just melted, lovely early spring flowers come into bloom.
Summer
Early July – mid-October River fun
Filled with rich greenery and the murmurs of the pure river, the gorge enters tourist season.
Many make their way to the riverbank and dip their toes in its icy waters.
Outside, temperatures often exceed 30° C, but inside the Kiyotsu Gorge Tunnel, it stays around 21 to 24° C and can even
feel chilly.
No sunlight penetrates into the tunnel, and a constant refreshing breeze blows off the river, providing it with natural
air conditioning.
However, the moisture-rich river air cools and condenses inside the tunnel, resulting in high humidity (over 90%), and
extreme differences in temperature inside and outside the tunnel persist throughout the summer.
Autumn
Late October – mid-November The fall foliage season
No paints on Earth can fully express the stunning beauty created by the interweaving of the stark bare rock walls and
vivid autumn foliage induced by the gorge’s extreme temperature differentials.
Fall is the season when Kiyotsu Gorge is at its busiest, and extreme crowding and congestion can be expected from
mid-October to late November.
The best time to see the area’s fall foliage starts from around the middle of October and lasts until the end of October
to the start of November.
The gorge’s green foliage begins to grow pale, brilliant yellows start to stand out, and eventually almost all of the trees
are covered in gold, but patches of crimson can also be seen here and there.
Due to the gorge’s spring avalanches and climatic variations, each year the conditions of the trees is different,
resulting in different color patterns every fall.
The leaves begin to fall off in mid-November in preparation for winter.
Winter
Mid-November – late May Winter snowscapes
Even for Niigata, a place known for snow, Kiyotsu Gorge experiences heavy snowfall.
The contrast between the roughly carved columnar jointing of the gorge’s cliffs and the white of the snow resembles an
ink painting.
In most years, the first snow of the season falls in late November. Most of the time, this snow melts away and does not
linger.
The true snows begin to fall and accumulate on the ground in mid-December.
The snow is powdery but abundant, and more than a meter can pile up in a single day.
Snow removal ensures that passage in and out of the area is still possible, but walls of snow greater than two meters high
enclose roads on either side, and small avalanches blocking cliffside roads are a frequent occurrence.
Note: The Kiyotsu Gorge Tunnel is closed from mid-January to March 31.
Hours of Operation
9:00～16:00
Tunnel hours
8：30～16：30
Tunnel fee
Adults (16+) ￥600
Children (6-15) ￥300
Children under 5 and persons with a physical disability Free
- ※ A discount of 50 yen/person is available to groups of more than 20 people.