
Owakudani (大涌谷), literally translated as the “Great Boiling Valley,” is an active volcanic zone that serves as the dramatic centerpiece of Hakone. This scorched crater was formed approximately 3,000 years ago following the last major eruption of Mount Hakone. Today, the area is a surreal wasteland of sulfurous steam vents, bubbling geothermal pools, and yellowed earth, providing a visceral reminder of the tectonic power simmering beneath the surface.
The valley’s most famous curiosity is the kuro-tamago, or “black eggs.” These are standard chicken eggs boiled in the naturally hot, sulfuric waters of the valley. A chemical reaction between the sulfur and the iron in the volcanic pools turns the shells a stark, charcoal black, though the inside remains a perfectly normal (and delicious) hard-boiled egg. Local folklore suggests that eating a single egg will add seven years to your life. Beyond the snacks, the area offers spectacular views of Mount Fuji on clear days, with the rising white steam plumes providing a stark, primordial foreground to the iconic peak.
Because Owakudani is a living volcanic site, visitor access is dictated by nature. High concentrations of volcanic gases can lead to sudden closures of the hiking trails and sections of the Hakone Ropeway. It is highly recommended to check for current gas warnings and volcanic activity levels at local train stations or through your ryokan before making the trip up the mountain.
| Visitor Information | |
|---|---|
| Address | 1251 Sengokuhara, Hakone, Ashigarashimo District, Kanagawa 250-0631 (Google Maps) |
| Opening Hours | 9:00 AM – 5:00 PM (Ropeway operating hours) |
| Price | Entry: Free / Black Eggs: ¥500 (pack of 5) |
| Website | Visit Website |
| Access | ||
|---|---|---|
| Station / Stop | Line / Transport | Access Details |
| Owakudani Station | Hakone Ropeway | The station is located directly in the heart of the volcanic valley. |
| Sounzan Station | Hakone Tozan Cable Car | Transfer to the Ropeway for an 8-minute ride to the valley. |
| Togendai Station | Hakone Sightseeing Cruise | Transfer from Lake Ashi to the Ropeway (approx. 18-minute ride). |