Ryusendo Cave: Underground Lakes, Stairs and the Route from Morioka in Iwate

This guide covers the underground lakes of Ryusendo Cave, the stairs and temperature inside, the history of its study, and the practical details for reaching it from Morioka.

The known portion of Ryusendo Cave runs a long way underground. This guide follows the route past the underground lakes, then turns to the practical details of getting there from Morioka.

Quick Facts

Item	Detail
Known length of Ryusendo Cave	4,088 m
Temperature inside the cave	Around 10°C all year round
Time to see Ryusendo Cave and the Ryusendo Shindo Science Museum	About 1 hour in total

The Route Past the Three Underground Lakes

Walk in and the route leads to the first underground lake, where the water depth has been measured. The second underground lake follows, with a measured depth of its own. The third underground lake closes the sequence, and its depth is on record as well.

During busy periods the tourist route becomes one-way, and visitors finish by climbing a flight of steps to a temporary tunnel exit.

Stop	Detail
First underground lake	Water depth 35 m
Second underground lake	Water depth 38 m
Third underground lake	Water depth 98 m
Climb to the tunnel exit during one-way routing	About 60 steps

Temperature and Stairs inside the Cave

The air temperature inside the cave holds steady through the whole year, whatever the season outside. Beyond the third underground lake, at the far end of the route, the stairs climb up and come back down, and the step count combines the way up and the way down.

Item	Detail
Stairs beyond the third underground lake	About 270 steps, up and down combined

Choosing When to Go

Choose a visit outside the busy season and the entrance and exit are the same; go in the busy season and the route becomes one-way, with a separate entrance and exit. The underground lake looks clearest in winter, when it does not rain and the water volume holds stable.

In winter the surface freezes, the drips from above stop, the ripples that disturb the surface settle, and the transparency rises further. When heavy rain or snowmelt raises the lake water, the flow grows stronger, stirs up the fine white silt on the lake bed, and the water looks cloudy.

History of the Cave Survey

The academic survey of Ryusendo Cave took place in the year the cave was designated a national natural monument. A cave research institute, the Nihon Dogaku Kenkyujo, was founded with the support of Iwaizumi Town after a comprehensive survey.

Item	Detail
Academic survey and national natural monument designation	1938
Founding of the Nihon Dogaku Kenkyujo	1967

The Park and Time on Site

Coin lockers are available in the park, which lets you leave a bag before heading into the cave.

If you prefer to go with a guide, browse guided tours near Ryusendo Cave.

Costs and Hours

Item	Detail
Admission to the cave and the Ryusendo Shindo Science Museum together, adult (high school students and older)	1,100 yen
Admission to the cave and the Ryusendo Shindo Science Museum together, elementary and junior high school students	550 yen

Season	Opening hours
October to April	8:30 am to 5:00 pm
May to September	8:30 am to 6:00 pm

Getting to Ryusendo Cave from Morioka

The route to the cave starts at Morioka.

1. Board the JR Bus Tohoku at bus stop 1 of the Morioka Station East Exit.
2. Ride from Morioka to Iwaizumi for about 120 minutes.
3. When paying by cash, take a numbered ticket when boarding.
4. Driving from Morioka via National Route 455 takes about 110 minutes.

Item	Detail
Adult bus fare from Morioka Station to Ryusendo-mae	2,710 yen
The first parking lot	About 400 m from the cave, 80 vehicles
The second parking lot	About 70 m from the cave, 47 vehicles