
Walk away with garnets, amethysts, rubies and sapphires at this little-known tourist spot.
Once you become an adult, it can feel like there are fewer things you can enjoy with the same unabashed freedom that you once had as a child. However, the other day, our reporter Maro came across something that nurtured her inner child for the first time in a long while, and it was located at a tourist facility in Yamanashi Prefecture called Saiseki no Kura.
▼ To be accurate, the place goes by the offical name “Koushuu Tennenseki Koubou Saiseki no Kura” (“Yamanashi Natural Stone Workshop Unpolished Gem Warehouse“), with “Koushuu” being the old name for Yamanashi.

As the name suggests, this facility specialises in stones and gems, which is apt, seeing as Yamanashi Prefecture has long had a thriving jewellery industry, and even has a gem museum dedicated to precious natural ores from all over the world. What makes Saiseki no Kura so popular is the fact that it offers a Gem Hunt for Adults, where you can rifle through a collection of small rocks and take any semi-precious stones and gems you find home with you!
▼ Saiseki no Kura is located about three minutes by car from JR Isawa Onsen Station.

When Maro arrived at the warehouse, which is free to enter, she first made her way past a collection of glistening natural ores, including an amethyst that was larger than her.


The gem hunt is located in a building next to this one, so that’s where she headed to next. This is where you’ll find a gem hunt for children and one for adults, the latter of which is divided into several courses, depending on the value of gems that can be found.

Maro opted for the standard 2,200 yen (US$15.40) course, which is guaranteed to contain one of nine types of gemstones polished by an artisan, in amongst other small chipped stones and craft stone replicas.
▼ The Gem Hunt has a time limit of 30 minutes, so time is a top priority for the gem hunter.

▼ The first task is to choose your excavation container.

The gemstones have already been buried by staff, so what kind of jewels you unearth depends on the container you choose. Each bowl has a comment attached to it, so you can use your intuition to help you make the all-important choice.
▼ “Are you sure it’s me — you won’t regret it?”

Mari chose a container with a picture of a mysterious man on it that really stood out to her.

Once she’d made her choice, there was no time to waste, as she only had half an hour to search for gems. Deftly using the spoon and tweezers provided, Maro dug through the stones to discover the hidden jewels.

The great thing about Gem Hunting for Adults is you can actually find a lot of gems. Just use the back of the spoon and the tweezers to rifle through the stones and you’ll find a bevy of colourful gems.

Maro couldn’t believe how much she’d harvested in just 10 minutes — there were major finds, like amethysts and crystals, in amongst other colourful stones. Many of these natural stones had holes in them, so they could easily be made into accessories.
▼ After about 15 minutes of digging with all her might, Maro found a gem that shone like none other.

The deep red stone was a garnet, which made Maro want to jump up and down in delight. This was the most coveted gem in her price category, so she was relieved to find it within the time limit.
She still had time for more digging, though, which was good because the excavation method required quite a bit of time and patience.

The trick to success, according to Maro, is to break up the pile with the back of the spoon and pick only the stones you want with the tweezers. Since you can only use these two implements, you can’t get everything you want in just 30 minutes, so you have to be selective to a certain extent.
▼ After digging for a few more minutes, Maro came across…another garnet!

Ordinarily, there’s only one gemstone per container, but on rare occasions, the person who went before you may have missed out on finding the gem, in which case there might be two gemstones in the container once staff have added to it.
Maro was super lucky to have found not one but two garnets, so she said a silent thanks to the mystery man who’d enticed her over to the container with the message, “You have a good hunch, don’t you? I don’t mind letting you choose.”

Maro continued to mine for gems, concentrating so hard on the task that when it was over her shoulders, neck, and eyes were sore. The 30 minutes seemed to pass by in the blink of an eye, but she was glad it ended when it did because if she’d continued any longer she might have suffered even more aches and pains. Still, it was so much fun that she became totally engrossed in the activity and totally lost track of time, and what she went home with was far more than anything she could’ve dreamed of.
▼ The tray in the back shows what her friend mined in the 30 minutes, while the tray in front is Maro’s haul.

All the stones can be taken home as is, or they can be processed into accessories like resin art or jewellery for an additional fee. Since Maro was able to collect two garnets, she wanted to turn her gems into earrings, but she didn’t have time to wait for them to be made or pick them up at a later date so she decided to make them herself at home.
She left totally happy and satisfied, praising it as the best tourist activity in Yamanashi Prefecture. Those who opt for the most expensive 10,000-yen course can even unearth rubies and sapphires, and different jewels appear every season, so you’ll want to come back again and again!
▼ Other stones you can find include topaz and peridot.

Children aged from three and up to 6th grade can also join in the fun with a gem hunt of their own, priced at 1,100 yen per person.

▼ Aside from the garnets, Maro’s other favourite finds from the day were these amethysts in various shapes.

While it takes about 30 minutes to hunt for gems, if you include walking around the museum and browsing the store, you can spend a good two to three hours here. Both adults and kids will love the fun of the hunt, and staff are incredibly kind and friendly, so Maro can’t wait to visit again in future.
It’s one of many hidden gems you can find in Yamanashi, which is also home to one half of Mt Fuji and its bright blue Fuji curry.
Site information
Koushuu Tennenseki Koubou Saiseki no Kura / 甲州天然石工房 彩石の蔵
Address: Yamanashi-ken, Fuefuki-shi, Isawa-cho, Kubonakajima 122-1
山梨県笛吹市石和町窪中島122-1
Hours: 8:30 a.m.-5:00 p.m. (Gen Hunting reception open until 4:15 p.m.)
Open year-round
Website
Images © SoraNews24
● Want to hear about SoraNews24’s latest articles as soon as they’re published? Follow us on Facebook and Twitter!
[ Read in Japanese ]

Secret tourist stop in Japan has a lift car that whisks you away to a mystery mountain destination
Real gems from Japanese arcade UFO catchers: Crane-caught riches, or a shiny scam?
This secret spring flower-viewing spot in Japan is yet to be discovered by international tourists
There’s something fishy about this mysterious tourist spot in Japan
Kyoto Station breakfast cafe is a hidden gem that tourists are yet to discover
Skyscraper sized Pokémon cards to appear in Tokyo all year long in Tocho projection mapping event
Yakuzen ramen restaurant in Tokyo is very different to a yakuza ramen restaurant
Ghibli’s Kiki’s Delivery Service returns to theaters with first-ever IMAX screenings and remaster
Tokyo Skytree turns pink for the cherry blossom season
Development of Puyo Puyo puzzle game for use in nursing homes underway
Highest Starbucks in Japan set to open this spring in the Tokyo sky
Japan has only one airport named after a samurai, so let’s check out Kochi Ryoma【Photos】
Osaka icon loses legs, restaurant says famous crab is exhausted
Shimane’s hidden travel sites, where you can escape the crowds and enjoy traditional Japan
Foreign tourists in Japan will get free Shinkansen tickets to promote regional tourism
The 10 most annoying things foreign tourists do on Japanese trains, according to locals
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Naruto and Converse team up for new line of shinobi sneakers[Photos]
Is Sapporio’s Snow Festival awesome enough to be worth visiting even if you hate the snow? [Pics]
Japan has trams that say “sorry” while they ride around town…but why?
Sakura Totoro is here to get spring started early with adorable pouches and plushies
Poop is in full bloom at the Unko Museums for cherry blossom season
Shibuya Station’s Hachiko Gate and Yamanote Line stairway locations change next month
Japan’s new “Cunte” contact lenses aren’t pronounced like you’re probably thinking they are
Japan’s newest Shinkansen has no seats…or passengers [Video]
Foreigners accounting for over 80 percent of off-course skiers needing rescue in Japan’s Hokkaido
Super-salty pizza sends six kids to the hospital in Japan, linguistics blamed
Starbucks Japan unveils new sakura Frappuccino for cherry blossom season 2026
Take a trip to Japan’s Dododo Land, the most irritating place on Earth
Is China’s don’t-go-to-Japan warning affecting the lines at a popular Tokyo gyukatsu restaurant?
Survey asks foreign tourists what bothered them in Japan, more than half gave same answer
Japan’s human washing machines will go on sale to general public, demos to be held in Tokyo
Starbucks Japan releases new drinkware and goods for Valentine’s Day
We deeply regret going into this tunnel on our walk in the mountains of Japan
Studio Ghibli releases Kodama forest spirits from Princess Mononoke to light up your home
Major Japanese hotel chain says reservations via overseas booking sites may not be valid
Put sesame oil in your coffee? Japanese maker says it’s the best way to start your day【Taste test】
No more using real katana for tourism activities, Japan’s National Police Agency says
Hey, Japanese taxi driver! Take us to the best sakura site in Yamanashi Prefecture!
We visit the “Naples of Japan”, a secret destination tourists don’t know about yet
The top 10 things foreign tourists visiting Japan want to do during Golden Week
Mystery Tourist Spot: Merlions in Japan?
Top 30 tourist sites in Japan: the most popular sightseeing spots for overseas visitors
Staircase National Highway: the only highway in Japan that cars can’t enter
Is Kyoto really as crowded with foreign tourists as they say?
Travelling to Japan soon? New entry requirements you need to know about
Retro vending machine corner is a hidden gem in the Japanese countryside
Travelling to Miyajima and Itsukushima Shrine? Best to be a glass-half-full type of tourist
Forbidden area at Japanese mountaintop shrine opens to the public for first time in 400 years
Beautiful Starbucks in Kyoto blends into its traditional landscape in more ways than one
Japan’s Three Most Disappointing Tourist Sites: Sapporo Clock Tower
Has the Mt Fuji Lawson blackout screen really stopped tourists from taking photos?
Bent postboxes in Taiwan are a heartwarming reminder to never give up
Shikayose: The Calling of the Deer in Nara with acorns and a French horn