The Great Boiling Valley (Owakudani in Japanese) is an active volcanic valley with hot springs in Hakone, Kanagawa. It has a high reputation as a tourist attraction all over the world. The Great Boiling Valley was formed following a volcanic activity of Mount Hakone, and is a sacred place where you can feel the beat of the Earth. We are going to introduce the Great Boiling Valley in detail, digging into its formation and the use of it nowadays.
The Great Boiling Valley, a well-liked tourist site at a volcano
The Great Boiling Valley is a geothermal and fumarolic area at Mount Hakone, a complex volcano. It is considered the symbol of Mount Hakone, for being the largest fumarolic area there. Now, as much effort has been paid to make the area visitor-friendly, the area has gained popularity as a tourist site. Not only can people get easy access to there by the Hakone Ropeway (cable car) or by car, but the safety measures are also implemented. Several Volcanic Alert Levels are set and if the concentration of volcanic gas increases, entry restrictions will be imposed beforehand. Besides the access and the safety measures, there are also cafeterias and souvenir shops at the Owakudani parking lot. As you can tell, the area has been made totally suitable for sightseeing. For those who live in countries without volcanoes, the Great Boiling Valley is decidedly a must-see. You must be impressed by the magnificent scenery of the great nature.
The formation of the Great Boiling Valley
The Great Boiling Valley was formed with the sediments from an explosion of Mount Hakone about 3100 years ago, and the pyroclastic flows and volcanic clastic materials from an eruption about 2900 years ago. Since that eruption about 2900 years ago, a lava dome (or volcanic dome) has been growing and the current Kanmurigatake has been hence formed. Following the eruption, phreatic eruptions often occur there, and the Great Boiling Valley has become one of the most famous active volcanoes in Japan.
Recent volcanic activities of the Great Boiling Valley
The volcanic activities of the Great Boiling Valley so far include earthquakes and small-scale phreatic eruptions. A phreatic eruption occurs when magma heats the groundwater until the water finally evaporates into steam and it explodes out of the ground. As there were a lot of volcanic activities in the valley in 2001 and 2008, since then, the crustal deformation indicating the rise of water vapour underground has been strictly monitored. The latest phreatic eruption was the one in 2015. At that time, entry restriction was imposed, and even the hot spring resorts nearby were affected.
Be alert! Volcanic gas can take lives
The volcanic products given off by the Great Boiling Valley contain not merely water vapour, but also volcanic gas. The main components of volcanic gas are hydrogen sulfide and sulfur dioxide, which are toxic. Volcanic gas does harm to health, or can even take lives. Despite of the limited access to the fumarolic area in the valley, when volcanic activity gets strong with right wind direction, the toxic volcanic gas may reach Owakudaya parking lot. For the reason of safety, in case your eyes or nose feel uncomfortable, or the smell gets abnormally strong, it is of vital importance that you leave immediately. Also be reminded that, people suffering from respiratory problems or heart diseases, those who are feeling not well, and pregnant women are advised not to enter the valley.
Now the Great Boiling Valley may seem scary to you, but remember that if you follow strictly the rules set up there, everything will be safe. Do keep alert when you are sightseeing there!
A gift from nature: the hot springs in Hakone
The Great Boiling Valley can be said to be the heart of the hot spring resorts in Hakone that do not boil their hot spring water. There are hot spring resorts which use the hot groundwater naturally heated by the water vapour and volcanic gas of the valley as their hot spring water, instead of boiling the water themselves. Then, you may be curious that how the groundwater is sent to the hot spring resorts. The answer is, the water is sent to the resorts through water supply pipes which are up to 15 kilometers long. The temperature of the water in wellspring is about 63°C, and when the water arrives in the bathtubs, its temperature is 42°C, which is perfect for a hot bath. Heated by water vapour containing volcanic components, the groundwater contributes to the wonderfully natural hot springs that do good to health.
Strolling around the Great Boiling Valley
Taking a stroll is the best way to enjoy the Great Boiling Valley! There is a natural walking trail connecting directly to the parking lot. The trail is just next to the fumarolic area, so you can closely feel the valley, which was called “Jigokudani” (literally “the valley of Hell”) in the old days until Edo period. It must be an unforgettable experience enjoying the desolate landscape with the smell of sulfur lingering around. In the middle of your walk, there is a tea house named “Kurotamago Teahouse” (literally “black egg teahouse”), making and offering the specialty of the valley – black eggs. However, in 2017, as of now, entry to the walking trail is prohibited due to safety measures.
Local specialty: black eggs
Black eggs (“Kuro-tamago” in Japanese), the local specialty of the Great Boiling Valley, is black on the surface, as the name suggested. The eggs are boiled in the volcanic water, which contains sulfur and iron. The iron sulfide resulted from sulfur and iron turns the eggshells black. The black eggs steamed in Kurotamago Teahouse are then carried to the souvenir shops nearby by ropeway. With a scent of sulfur, the black eggs are said to be much more delicious than the usual eggs! When you are visiting the Great Boiling Valley, do not forget to have a taste of the black eggs!
Access to the Great Boiling Valley
First of all, from Tokyo station, ride in a shinkansen (a bullet train) or a local train to Odawara station, which is in Kanagawa prefecture. It is about 35 minutes from Tokyo station to Odawara station by Tokaido Shinkansen. Otherwise, it takes 1 hour and 20 minutes by a local train on Tokaido Line. The fare for shinkansen is twice that for a local train. When you arrive at Odawara station, take the Hakone Tozan Railway and get off at the final stop – Gora station. The ride is about 30 minutes. From Gora, change to the Hakone Tozan Cable Car and get off at Sounzan Station, where you take the Hakone Ropeway. Finally, you will arrive at Owakudani station in 10 minutes. From Tokyo station to the Great Boiling Valley, Owakudani station, it takes at least 2 hours and 30 minutes in total.
Feel the breath of the Earth in the Great Boiling Valley
The Great Boiling Valley, with a history of 3000 years, is a volcanic area where you can feel the breath of the earth. While it can be a dangerous place threatening lives, oppositely it is also a place full of grace of nature. Enjoy sightseeing in the valley, and most importantly, do not forget to obey the rules!