Owakudani: The Volcanic Valley and the Black Eggs

Owakudani sits on an active volcano, and that is not decorative. Hydrogen sulphide levels are monitored continuously, and when they rise the ropeway suspends service and the walking trails close.

This has happened repeatedly, including a multi-year closure of the walking paths after the 2015 volcanic activity. Sections reopen and re-close on the readings. It can change on the morning.

So: check the Hakone Ropeway's official status page the day you go, before you commit to the loop. When the ropeway is down, a replacement bus runs around the valley — you still complete the loop, you just do not get the crater view or the eggs.

People with asthma, heart or respiratory conditions are advised against the valley floor even when it is open, and that advice is posted for a reason. The smell alone is substantial.

Kuro-tamago are ordinary eggs boiled in the sulphurous hot springs. Iron in the water reacts with the sulphur and coats the shell in black iron sulphide; the egg inside is a normal boiled egg and tastes like one.

Local tradition holds that eating one adds seven years to your life. They are sold in bags of five at the top station, which by that arithmetic is thirty-five years, and nobody has ever offered a satisfying explanation for the discount.

It is a tourist ritual and it is a good one — you eat them standing in the wind at a thousand metres with steam venting out of the hillside behind you. Bring cash; the shop is not always card-friendly, and the queue moves fast.

On a clear day the ropeway crossing over Owakudani gives you the whole thing at once: a bare, steaming, yellow-grey valley directly below the cabin, and Mount Fuji on the horizon beyond it.

That combination — active volcanism in the foreground, Japan's most famous volcano in the background — is the single best view in Hakone and one of the better ones near Tokyo. It is also weather-dependent in the usual way: Fuji hides behind cloud far more often than not, and the odds are best in the cold, dry months.

The valley was formed by an eruption roughly three thousand years ago that collapsed the side of the older volcano. What you are looking at is the scar, still venting.

Owakudani is the high point, literally, of the Hakone loop: Tozan railway from Hakone-Yumoto, cable car up from Gora, ropeway over Owakudani, then down to Togendai for the Lake Ashi boat, and a bus back.

The loop runs in both directions and most people go clockwise, which puts Owakudani mid-morning. That is the right call — cloud tends to build over the day, so the Fuji view is more likely early.

The Hakone Free Pass covers every leg including the ropeway and the boat, and pays for itself if you do the full circuit. Allow the whole day. Trying to compress the loop into an afternoon is how people end up standing at a ropeway station watching the last cabin go without them.