Lake Mashu Observatory No. 1: The Classic View, Parking and the Fog

By Chaporo, a Sapporo local Published
Lake Mashu Observatory No. 1: The Classic View, Parking and the Fog

Quick answers

  • The main observatory, with the classic view of Mashu blue, a shop, a café and toilets
  • Parking is 500 yen from late April to early November and free the rest of the year; the ticket also covers Mt. Io on the same day
  • Observatory No. 3 is a few minutes away and quieter; Ura-Mashu is on the far side, about an hour away
  • The fog can change quickly: if the lake is hidden, try No. 3 or wait a while

Lake Mashu is the deep blue lake inside a crater in eastern Hokkaido, and Observatory No. 1 is where most people see it first. It is the main observatory, with a large car park, a shop and toilets, and the view that matches the photos. When I went, it felt like the reference point for the lake: see it here, then decide whether to visit the quieter observatories.

What is Lake Mashu?

Lake Mashu is a caldera lake in Teshikaga, inside Akan Mashu National Park, and one of the clearest lakes in the world. On a clear day the water is a deep, intense blue, called Mashu blue, and that color is what everyone comes for. You cannot get down to the water; you look down on it from observatories on the crater rim. It is also famous for fog, so the lake can look completely different from one hour to the next.

The view from Observatory No. 1

Lake Mashu and its island seen from Observatory No. 1

From the viewing area the lake opens up below you, and the scale and the depth of the blue hit you at once. What I noticed most was that the view looks just like the photos, which is not true of every famous place. It is the one I would send a first-time visitor to.

The viewing area at Lake Mashu Observatory No. 1

Allow 20 to 30 minutes to take in the view, take photos and look around the shop.

Facilities: Lake Mashu Kamuy Terrace

The shop and rest house at Lake Mashu Observatory No. 1

The building at the observatory, Lake Mashu Kamuy Terrace, has a shop, a café and toilets, so it is easy to wait out a change in the weather. The shop is open from 8:30 to 17:00 and closes over New Year. The observatory itself is open at all hours, except when Prefectural Road 52, the road up, is closed in bad weather.

Which Lake Mashu observatory should you visit?

There are three observatories, and the right one depends on how you want to see the lake.

ObservatoryBest for
Observatory No. 1A first visit: the classic view, with a shop, toilets and an easy road
Observatory No. 3A slightly quieter view, closer to the water, a few minutes further along the same road
Ura-Mashu ObservatoryPeace and atmosphere, on the far side of the lake

Observatories No. 1 and No. 3 are close together on the west side of the lake, so it is easy to see both, and if one is in fog you can try the other. Ura-Mashu is on the opposite side and about an hour away by car, which is possible on the same day but worth it only if you want the quiet.

Lake Mashu Observatory No. 3: The Quieter View of Mashu BlueA local's guide to Lake Mashu Observatory No. 3: how the view compares with Observatory No. 1 and Ura-Mashu, who it suits, how long to stay, and what to do about the fog. Ura-Mashu Observatory: The Quiet Far Side of Lake MashuA local's guide to Ura-Mashu Observatory on the eastern side of Lake Mashu: how it compares with Observatories No. 1 and No. 3, where it is and how to fit it in, the fog, how long to stay and what to know.

Parking and access

The car park holds about 125 cars and costs 500 yen for a car from late April to early November; the rest of the year it is free. The same ticket also covers one visit to the car park at Mt. Io, the steaming volcano nearby, but only on the same day, so it pays to see both on one day.

You need a car to get here. JR Kawayu-onsen Station is about 20 minutes away by car, and Memanbetsu Airport about an hour and 20 minutes.

What about the fog?

Lake Mashu is famous in Japan for its fog, and there is even a popular song about it. The fog can change quickly, so if you arrive to a white wall, try Observatory No. 3 nearby or wait a while before you give up.

Lake Mashu on a road trip

Lake Mashu fits into a loop with Lake Kussharo, Mt. Io and Lake Akan, with a night at Kawayu Onsen.

Lake Mashu, Lake Kussharo and Lake Akan: A Local's Eastern Hokkaido Road TripA two-night road trip around Lake Kussharo, Lake Mashu and Lake Akan to the Kushiro Wetland, from a Sapporo local who drove it: the order that works, what each lake is like, the boat to the marimo, and weather and driving tips.

FAQ about Lake Mashu Observatory No. 1

Q1. Is there a fee at Lake Mashu Observatory No. 1?

Viewing is free. Parking costs 500 yen for a car from late April to early November and is free the rest of the year.

Q2. Which Lake Mashu observatory is best?

For a first visit, Observatory No. 1: the classic view and the best facilities. Observatory No. 3 is quieter and close by.

Q3. What if Lake Mashu is covered in fog?

Try Observatory No. 3 nearby, or wait a while; the fog can change quickly.

Q4. How long do you need at Lake Mashu?

About 20 to 30 minutes at Observatory No. 1. No. 3 is a few minutes' drive away if you want a second look.

Q5. Can you reach Lake Mashu without a car?

It is hard. Buses are limited, so a rental car from Memanbetsu or Kushiro Airport is the practical way.