Bicycles zipping across pure white, snow-covered fields.

Can you believe this is a lake?

It's all iced over.

They're on a lake covered in a thick sheet of ice.

You can only see this sort of scenery here.

Today, we'll bike snowy roads in below-freezing weather,

and discover spectacular scenery that can only be seen atop this icy lake.

Ah, look, look!

What mysteries await?

Wild Hokkaido!

Our location today is the Tokachi region of central Hokkaido.

It looks pretty chilly.

It's minus eight.

Good day for cycling.

It's not too cold.

Even in just minus eight degrees Celsius,

cycling is a breeze for Englishman David Barnett.

He is a veteran cycling guide,

and even competes in mountain biking competitions.

This time, he's going to try cycling on snow-covered roads.

So, today, we're going on about a 20-kilometer ride up to the lake.

The lake is frozen over, because it's obviously mid-January.

And we'll see something that I've always wanted to see.

David's eager to be at this lake especially in winter.

But he needs specific equipment to get there.

On this trip, he'll use a winter bike.

The tires have metal pins for tread, designed for winter conditions.

But with the spikes, there's no chance of slipping.

No sideways slipping. Perfect.

The pins will grip the surface of the road,

so they won't slip on snow or ice.

David will cycle to the lake with his guide buddy, Ishizuka Yuya.

Okay, we're going to set off? Let's go.

About a 20-kilometer ride.

Maybe one hour and a half.

Maybe.

It depends on the road conditions.

Even on icy urban roads, there's no risk of slipping thanks to spike tires.

But for those of us traveling on foot,

it's much more difficult to stay upright.

Now for the "SENSEI's Tip."

Let's find out how to avoid slipping on icy roads.

It's tough walking on icy streets!

Before taking a fall, try reading this safety pamphlet.

For walking safely on winter roads in Hokkaido,

translated into English, Chinese, and Korean.

Walking behavior most likely to result in a fall.

And then suggested winter clothing and lots of information about winter.

When walking on icy roads,

the key is to place the whole sole of your foot flat on the road.

Take small steps, but don't rush.

Take your time to keep from slipping and falling.

So maybe next time you come to Hokkaido,

you can find that information useful.

David is back on his way to the lake,

cycling over snow-covered roads.

After leaving the city, the straight road continues into the mountains.

Nice straight road. Ah, that feels really good.

No cars. Just the sound of the tires on the road.

After riding for about 30 minutes, they reach a mountain road.

Here, they discover something unusual.

Below the bridge, there's another bridge.

Right. Let's stop here and have a look.

- Really cold.
- Yeah.

The old railway bridge.

It's an abandoned railway track.

This old railroad bridge was used a long time ago.

Around here, there's quite a few of these old concrete railway tracks.

Railway bridges.

So, this time, we've come to see the old concrete railway bridges.

The one we're going up to now is the other,

so later we'll see that one, hopefully.

There are many remnants of disused railway tracks around these parts.

Finding these abandoned tracks was on the list of things to see this trip.

So, they continue to climb the mountain hoping to find more railroad remains.

The slope's getting steeper.

It's quite a climb.

Although the mountain is steep,

it's the perfect amount of exercise for the two cyclists.

Just then, something comes into view ahead.

The dam?

Yep, that's the dam on the right.

Dam over the mountains. So beautiful!

So that's the Lake Nukabira and the reservoir behind the dam.

Nearly there.

Beyond the dam is Lake Nukabira, their destination for today.

So, the frozen lake on the right.

They're almost there.

Suddenly, they noticed movement up ahead.

Some more deer there.

Lots of deer.

Four or five.

So many.

- A whole herd.
- Maybe a family.

They've encountered a herd of deer.

It's almost like the deer have come to welcome them to the lake.

It's taken them 1 hour and 30 minutes of cycling to reach Lake Nukabira.

So we're here.

Finally.

So, the other side over there is the lake.

So, maybe we'll get some warm clothes on and get ready?

This is Lake Nukabira.

It has a circumference of 34 kilometers.

Although it's a vast lake, it completely freezes over in winter,

which makes it possible to ride across by bike.

So, we've got a license.

So, you've got permission to ride the bike on the lake.

Applying for a permit in advance

allows you to ride on a designated course on the lake.

There's powdery snow on the lake's surface,

so they'll change bikes to ones that won't sink in the snow.

From here, we're going to be going on to the lake,

so we're going to be using fat bikes.

The fat bikes are much better for deeper snow and softer snow.

The fat bike tires are twice as thick as the spike-tread tires,

which means they can ride over fresh, soft snow, without sinking.

They're ready to begin ice cycling.

So, this is the start of the lake.

Are we on the lake now?

Yep, can you believe this is a lake?

It's all iced over.

Let's go.

So the ice is about 40 centimeters thick

and on top of that we've got snow of about 20 centimeters.

The bikes glide across the lake.

This trail is nice and compact,

but it's best that we're riding on fat bikes.

The fat bike tires help them ride through the fluffy snow.

It's really quite tough right now.

The snow is really quite soft and deep,

so it makes it really quite difficult to ride.

But because we're on the fat tires, it's a little bit easier.

You can only see this sort of scenery here.

Perfect white snow, blue sky, this is great.

There's a sight at this lake that only appears in winter.

David spotted it.

The ice on the left there.

This is the ice on the top of a tree stump.

Blocks of ice appear to be balancing on top of tree stumps

scattered around Lake Nukabira.

How does the ice get up there?

It's a dam, so the water level changes,

so the water level goes down and the ice stays there.

As Lake Nukabira is a reservoir, during winter,

the water level is lowered to generate power.

When that occurs,

the ice on the surface remains on the tops of the tree stumps.

The formations are known as "mushroom ice."

It's a winter scene unique to reservoirs of dams.

It's pretty rare, apparently.

David says there's even more unique scenery to be found here.

They've reached the center of the lake.

Maybe if we dig here?

Ah, look, look!

You see? Underneath.

Inside the ice beneath the snow, there appears to be something white.

What could it be?

Let's see what happens if hot water is poured over the ice.

Look at that.

Ice bubble. Beautiful, yeah?

Yeah, so beautiful.

I've never seen this.

Yeah, so, the different layers are like 3-D.

These are ice bubbles.

They form when methane and other gasses

that are released from the bottom of the lake

become trapped in the ice.

As the ice increases in thickness, the bubbles freeze in multiple layers.

Beautiful. Like art.

It's nature art.

Natural art, yeah.

It's worth it, yeah?

Beautiful.

Then, at last... At the far end of the lake,

the winter landscape David has been looking forward to the most.

Almost there.

We're here.

So, look at that, we've got the old bridge.

Wow, beautiful, yeah?

Stretching over the top of the snowy plain

is a 130-meter-long railroad bridge,

which fell out of use once the dam was completed in 1955.

In summer, because of the water in the lake, you can't get close.

But in winter, the lake freezes over for just a short time

so you can cycle right up to the bridge.

This is what David was looking forward to the most.

It's the first time I've been here in winter.

It was even better than I imagined.

The white snow makes the scenery more dramatic.

But in winter, it's much better.

It's better than I expected.

David is also experiencing this scenery for the very first time.

He can even see the weathered condition of the bridge from up close.

When the water comes up in summer,

the concrete deteriorates, and then in the winter,

it freezes and then contracts and expands.

It's just like, falling apart.

Every year, they say, "It's going to fall down, it's going to fall down."

So, maybe in a few years' time, maybe it won't be here anymore.

So, we have to take advantage and come and see it while we can.

Over a period of 70 years,

the railroad bridge has been exposed to harsh conditions

by being repeatedly submerged, dried, and frozen.

Getting up close by bike to the slowly deteriorating relic

has left a lasting impression.

You can ride on the snow in many places,

and things are here that you can see only here, unique to this place.

It's a really good place.

The frozen-over Lake Nukabira, in the center of Hokkaido.

Here, we encountered a range of scenery found nowhere else in Japan,

shaped by the region's extreme winter climate.

Wild Hokkaido!

takes you on great activities in the great outdoors of northern Japan.

Join us next time for another adventure!