LET'S ODEKAKEExploring Japan's Limestone Caves: Escape the Summer Heat Underground

As the scorching summer sun casts its unrelenting rays upon us, underground worlds providing respite from the fiery heat beckon to be discovered. Nestled beneath the earth's surface, limestone caves stand as silent witnesses to the passage of time, offering a tantalizing escape from the high temperatures above ground and a mesmerizing journey into the heart of the earth's geological history. From dazzling stalactite formations that glisten like icicles to the mysterious artwork etched within the cavernous walls, caves are an often-forgotten place where you can cool down in summer.

We will introduce you some of the best limestone caves to visit during the hot Japanese summer, both near Tokyo and further afield.

The largest caves in Tokyo, these Caves are located in Okutama, in the Tama region. This is an area famous for hiking and river activities, so there is plenty to do for a full day trip. Inside the caves, you can see stalactites and stalagmites, along with fascinating underground shrines and holy carvings. And the best bit? It's only 11 degrees Celsius inside! No need for aircon there.

In the past, these caves were a holy place for monks from the Buddhist Shugendo sect, and several shrines and carved statues that are over 1,000 years old can be found inside.

The caves are illuminated by coloured LED lighting so that visitors can see the spectacular rock formations inside. There is a walking route inside that runs for 800m out of the 1270m total (the rest is not accessible), and as you traverse the route, music will accompany you, which makes for an interesting experience.

After leaving the caves, head to the Okutama River for fun water activities like swimming, fishing or rafting.

Official website: http://www.nippara.com/nippara/syounyuudou/ (Only Japanese website)

The Otake Limestone Caves have been open to the public since 1962 and are a great place for Tokyo residents to escape the heat in summer, being located in the far Western reaches of Tokyo in the Okutama region, like the Nippara Caves.

Visitors can explore a 300m section of the cave's tunnels, which will involve some climbing and crouching down to squeeze through narrow tunnels and low roofs. Don't worry, helmets are provided.

These caves can be combined with a day hike such as climbing Mt. Odake, or Mt. Mitake which is also in the vicinity. If you want more time to explore, there is a campsite next to the caves so you can stay the night and make it a full weekend trip.

Official website: https://tokyowestside.com/category/detail/otake-limestone-cave.html

With the word "ice" in their name, the Narusawa Ice Caves certainly sound like a good way to cool off in summer in Japan.

The caves are located in the Aokigahara Forest near Mt. Fuji and Lake Kawaguchiko and they reach as far as 21m underground. They were formed when Mt. Nagao erupted in 864 and the flowing lava from this eruption hollowed out these vast underground caverns. The cave is about zero degrees year-round (yes, zero, bring a sweater!) so you will definitely feel nice and cool.

Nearby are the Fugaku Wind Caves which you can visit at the same time using a special pass that offers entry to both caves.

There are also many sightseeing opportunities in the vicinity, like the traditional village of Saiko Iyashi-no-Sato Nenba, or the Saiko Wild Bird Park. Feel free to explore all on offer at Kawaguchiko or even Hakone as well – this can definitely be a full weekend trip.

Official website: https://www.yamanashi-kankou.jp/english/recover/narusawa-ice-cave.html

In Chichibu in Saitama are 34 temples that are part of the "100 sacred Japanese Kannon Temples" pilgrimage route. One temple included in this route is the Hashidatedo Temple, dedicated to the horse-headed Bato Kannon. The most interesting part of the temple is the Hashidate Limestone Cave where visitors can enter the depths of Mt. Buko. It is said that you can traverse the dim and narrow tunnels before emerging reborn, making this a highly spiritual experience.

The cave contains some ladders to climb and low roofs, so you will need to bend down quite a bit, and be prepared to get your clothes a bit dirty. Sounds like a mini-adventure! Afterwards you can visit the adjacent café or soba restaurant to refresh.

Below the cave site are the Iwakage Ruins, where you can see how ancient Jomon era people lived.

It only takes about 20 minutes to traverse these caves, so it's best to combine with some hiking in the Chichibu National Park, or visit the wonderful Chichibu Muse Park nearby.

Official website: https://www.chichibu-geo.com/en/geosite/geosite07/

The Hida Daishonyudo, or “Great Limestone Cave”, is 800m above sea level – the highest limestone cave in all of Japan. Elevation plus cave sounds like a very refreshing summer retreat. Inside, you can explore 800m of the tunnels, and interestingly, they also advertise that pets are allowed inside, so bring your pups! The paths are not very slippery unlike some caves, so this is a good option for kids.

The passages have been illuminated with coloured lights, so there are no visibility issues in these caves. Apparently the red and blue lights are to prevent moss from growing, while there is a rainbow tunnel that connects Cave 1 to Cave 2. Try and spot the helictite, a curvy stalactite that is rare to see. There is also a wine storage area in the cave, ingenious!

Next to the entrance is the Ohashi Collection Kan Museum, where you can see over 1,000 artworks from around the world. The entry fee is included in the cave ticket.

Official website: https://www.syonyudo.com/en/

Ryugado is one of the largest limestone caves in Japan, and its name means “dragon river cave” – now that sounds like an adventure. While you won't find any dragons inside, you will see stalactites and stalagmites galore over the 1km path that is open to the public. There are also historic objects and carvings from the Yayoi period inside.

The caves were formed over 175 million years and are the natural habitat to almost 100 different species of animal. Due to its unique habitat and impressive formations, the caves were declared a Natural Monument of Japan in 1934.

Colourful lights have been placed along the cave's path, along with projection mapping and music, so this is more of a magical experience than a spooky one. The massive blue-lit waterfall will inspire you as you stand there and listen to the music composed to accompany the flowing water.

If you are after adventure, book a guided adventure tour which will take you to sections of the cave that is not open to the general public.

Official website: https://www.syonyudo.com/en/

In Yamaguchi Prefecture you will find Akiyoshidai, Japan's biggest karst plateau, and a very nice place for walking, with green plains filled with white limestone pinnacles. Millions of years ago, this entire area was a coral reef!

Under the karst is Akiyoshido, the longest limestone cave in Japan. 1km of the caves are open to the public, and are a must-see in Yamaguchi. The main paths are paved and well-lit, so very accessible to anyone. Along the main route are natural formations such as underground waterfalls and bright blue lakes, with explanations provided.

For the adventurous among you, there is an "adventure course" which involves more scrambling up rocks and squeezing through tight spaces. If you're after a really exciting adventure, you can take a 2-hour tour through the nearby Kagekiyodo Cave, which we highlu recommend!

Official website: https://akiyoshidai-park.com/en/spot/akiyoshi-do.html

The Fujido Cave is 2.2km long, making it the longest cave in the Kanto area. It takes between 30-60 minutes to walk the full route, so it is one of the more time-consuming cave options to explore.

Fujido was discovered about 400 years ago by Buddhist monks and has since been designated a Natural Monument of Gunma Prefecture.

To enter the cave, you first cross through a manmade 120m tunnel, then ascend a staircase into the cave itself. Inside the cave is only 11 degrees, so you will feel like you've stepped into winter!

In the area is the Ueno Sky Bridge, which offers a slightly scary crossing with amazing views of the surrounding nature. Kids may also enjoy the Kanna Dinosaur Center.

Official website: https://www.visit-gunma.jp/en/spots/fujido-cave/

Ryusendo is another of the three biggest limestone caves in Japan. The inside is a constant 10 degrees throughout the year, and is colourfully illuminated with LED lights. Outside the cave is a freshwater tap coming directly from the mountain which you are allowed to drink from.

The caves are known for their startlingly blue underground lakes, with water so transparent you can see the bottom. If you are okay with climbing a lot of stairs, head to the observation deck where you can see one of the lakes from directly above.

In the area are nice riverside walks, and the Ryusendo Science Museum is definitely worth a visit.

Official website: http://www.iwate-ryusendo.jp/en/

Way down south, between Kyushu and Okinawa, are a group of islands known as the Amami Islands. If you are looking for a serious spelunking adventure, you need to head to Okinoerabu Island, which has over 300 limestone caves! While you can visit the Shoryudo Cave yourself, most people book a special adventure tour which comes with the necessary gear and guide.

These caves are said to be the most beautiful in Japan, and you can combine caving with idyllic white sandy tropical beaches and lush green jungles. The islands are also a good place to see sea turtles in their natural habitat.

Official website: https://www.kagoshima-kankou.com/for/attractions/52132

This is not an exhaustive list of all the limestone caves in Japan, but it is a good place to start. Hopefully you will be inspired to visit some of these caves and cool down this summer in a unique and interesting way.