Topographic map of Japan: the GSI map, explained

What is the GSI map?

GSI is Japan's national mapping agency, known in Japanese as Kokudo Chiriin (国土地理院). It is part of the Ministry of Land, Infrastructure, Transport and Tourism and is based in Tsukuba. It surveys the country, maintains the national control points and height network, and publishes the official map of Japan.

The map every Japanese hiker knows is the 1:25 000 topographic map, the chikeizu (地形図). It covers the entire country in several thousand sheets, with 10 metre contours, footpaths, huts, vegetation and a set of map symbols that is taught in Japanese primary schools.

The same data is published online as GSI Maps (地理院地図), a seamless map that anyone can browse for free. The map on this page is that one: the standard edition, the pale edition made for drawing things on top, and GSI's seamless aerial photography.

How the map is made, and which GSI map is which

GSI maintains a national digital base map compiled from aerial photography, airborne laser surveys and field checks. Contours, roads, buildings, rivers, vegetation and place names are stored as data and drawn into map tiles at each zoom level. At the closest zooms you are looking at the same content as the 1:25 000 sheets.

GSI content is published under Japan's Public Data License, which allows free use as long as the source is credited. That is why the official map can appear in apps and on pages like this one. Here is the family in one table.

• Standard map (標準地図) (Multi-scale, digital): The full-colour official map: ochre contours, trails, buildings, symbols and Japanese labels. This is the Topo edition on this page and in Traverse.
• Pale map (淡色地図) (Multi-scale, digital): The same map in a washed-out palette. It is designed as a background, so a route, a slope layer or a hazard zone drawn on top stays readable.
• Seamless photo (シームレス空中写真) (Imagery): GSI's most recent aerial photographs joined into one layer, with satellite imagery at small scales. Flight dates vary from place to place.
• English map (Overview scales only): GSI publishes an English-labelled edition, but only at regional zoom levels. Once you zoom in to hiking detail, the map is in Japanese. Traverse includes it for orientation.
• 1:25 000 paper sheets (1:25 000): The printed chikeizu, sold by sheet. Still the reference for navigation in the Japanese mountains, and what the digital map is drawn from at close zooms.

How to read the GSI map

You can read most of this map without reading Japanese, because the terrain and the symbols carry the information. Each entry below has a button that moves the live map to a place where you can see it for real.

• Ochre contour lines: Each line joins points of equal height. On the 1:25 000 base the interval is 10 metres, and every fifth line, at each 50 metres, is drawn thicker. Tightly packed lines mean steep ground. Around Yarigatake they almost merge, which is what a 3 000 metre rock spire looks like on paper.
• Dots with numbers: Spot heights in metres. Summits, cols and junctions carry them. A small triangle marks a triangulation point, a surveyed summit marker you can often find on the ground as a stone post.
• Dark dashed lines: Footpaths (徒歩道). This is how hiking trails are drawn. The map does not grade them, so a dashed line may be a graded path or a chained scramble along a ridge. It also shows no walking times, which is why Japanese hikers pair it with a commercial hiking map.
• Purple dash-dot lines: Administrative boundaries. In the Japanese Alps the prefecture border often runs along the main ridge, right on top of the trail. It is the most common thing visitors mistake for a path, so check the colour before you follow it.
• Small orange buildings with a name: There is no dedicated hut symbol. Mountain huts are drawn as buildings and labelled. Look for the endings 山荘 (sansō), 小屋 (koya) and ヒュッテ (hyutte). 避難小屋 (hinan-goya) is an unstaffed emergency shelter.
• Fields of small dots and rock drawing: Scree, gravel and bare rock. Above the treeline in the Northern Alps most of the ground is drawn this way. Hatched cliff symbols mark drops that the contours alone would understate.
• Green lettering: Names of roads and trails are set in green. On Mount Fuji each of the climbing routes is named this way. The characters 登山道 (tozandō) mean climbing trail, and 合目 (gōme) marks the numbered stations on the way up.
• Japan's map symbols: 卍 is a Buddhist temple, a torii gate is a Shinto shrine, 〒 in a circle is a post office, an X in a circle is a police station, 文 is a school and ♨ is a hot spring. They are useful landmarks in a town, and a temple or shrine symbol high on a mountain usually marks a summit shrine.
• Yellow and coloured roads, orange blocks: Main roads are filled in colour by class and built-up areas are drawn as orange buildings. Railways are striped lines with stations named in 駅 (eki). Useful for working out how you reach a trailhead by train and bus.
• Small repeated marks between contours: Vegetation symbols. Separate marks exist for conifer forest, broadleaf forest, bamboo grass and creeping pine (haimatsu), the knee-high pine that marks the top of the treeline in the Japanese Alps and Hokkaido.

1. Expect the shading to disappear: At overview zooms the GSI map has grey relief shading. Zoom in to hiking detail and it drops away, leaving only contours. Find the ridges and valleys while the shading is still there, then zoom in. Turning on 3D in the map on this page keeps the shape readable at any zoom.
2. Follow the thick contours: Index contours fall every 50 metres. Count them between the hut and the summit and you have the climb, to the nearest 50 metres, without reading a single label.
3. Match the label endings: You do not need to read a name to know what it is. 岳 and 山 end mountains, 沢 and 谷 end valleys and streams, 峠 and 乗越 are passes, 小屋 and 山荘 are huts. The glossary below lists the ones that matter.
4. Check it against the photo: Switch to the Aerial edition to see whether a slope is forest, scree or snow patch, and whether the trail is visible on the ground.

Browse the live Topo map

This page loads the real GSI Japan tiles in an interactive map, with Topo and Pale and Aerial and shortcuts to Yarigatake (Northern Alps), Mount Fuji (Shizuoka / Yamanashi), Kamikochi (Nagano), Tateyama Murodo (Toyama), Asahidake (Daisetsuzan, Hokkaido), Higashiyama (Kyoto).

Japanese map words for hikers

Place names on the GSI map end in a character that tells you what the feature is. Learn to spot these endings and the map becomes readable.

山 · yama, san

Mountain

岳 · dake, take

High or rugged peak

峰 · mine, hō

Peak, summit

尾根 · one

Ridge

峠 · tōge

Pass

乗越 · nokkoshi

Col, a crossing point on a ridge

沢 · sawa, zawa

Mountain stream or gully

谷 · tani, dani

Valley

川 · kawa, gawa

River

滝 · taki, daki

Waterfall

池 · ike / 湖 · ko

Pond / lake

雪渓 · sekkei

Snow gully that lasts into summer

岩 · iwa

Rock, crag

平 · daira, taira

Plateau, flat ground

原 · hara, bara

Open plain or moor

登山道 · tozandō

Hiking or climbing trail

登山口 · tozanguchi

Trailhead

新道 · shindō

"New trail", a named route

林道 · rindō

Forest road

山荘 · sansō / 小屋 · koya

Mountain hut

避難小屋 · hinan-goya

Unstaffed emergency shelter

水場 · mizuba

Water source

温泉 · onsen

Hot spring

神社 · jinja / 寺 · tera, ji

Shinto shrine / Buddhist temple

橋 · hashi, bashi

Bridge

駅 · eki

Railway station

Check the map against the ground

A topographic map is an interpretation. The aerial edition is the evidence it was drawn from. GSI joins its most recent aerial photographs into one seamless layer, and switching between the two is the fastest way to understand a piece of Japanese mountain terrain you have never seen.

Try it on Yarigatake. On the map the summit is a knot of contours with dots around it. On the photo you can see the spire itself, the scree fans below it, the huts on the shoulder and the lines the trails take through the rock.

Keep in mind that the photographs were flown on different dates and in different seasons, so neighbouring areas can disagree about snow, and a photo tells you nothing about this week.

What the map does not tell you

• It has no walking times, trail grades or difficulty ratings. Japanese hikers get those from commercial hiking maps and recent trip reports.
• A dashed line is not a guarantee. Trails are rerouted or closed after typhoons, landslides and volcanic activity, and the map can lag behind.
• It shows nothing about volcanic alert levels, winter snowpack, avalanche terrain or river levels, all of which decide whether a route is reasonable on a given day.
• Detailed labels are in Japanese only. The English edition stops well short of hiking scale.

Use the GSI map in Traverse

Traverse is a mountain mapping app for the web and iPhone. All four GSI editions are in it, drawn on real 3D terrain, together with the Japan-specific layers the base map leaves out.

• The GSI map in 3D: At hiking zooms the official map is contours only, with no shading. Draped over 3D terrain, those contours turn back into ridges, gullies and faces.
• Slope angle on top: Shade steep ground over the pale edition to see avalanche terrain and the gentler line around it.
• Japan-only hazard layers: Official landslide and flood zones, mapped avalanche terrain, and volcanoes with their current alert level.
• Routes, GPX and offline: Draw a route or import a GPX, get distance, ascent and a profile, then download the area for use without signal.

A Traverse account is free and includes the Traverse, Summer, Winter and Satellite maps with slope angle and aspect. Official national maps, including the GSI maps of Japan, are part of Traverse Pro.

Create a free Traverse account · Download Traverse for iPhone

Frequently asked questions

Is the GSI map of Japan free?

Yes. GSI publishes its maps online under Japan's Public Data License, which allows free use with a credit to the source. You can browse them at GSI Maps, and on this page. Printed 1:25 000 sheets are sold separately.

Is there an English version of the Japanese topographic map?

Only partly. GSI publishes an English-labelled edition, but it covers overview scales, not hiking detail. At the zoom levels you navigate with, labels are in Japanese. Learning a few dozen name endings, such as 岳 for a peak and 沢 for a stream, gets you most of the way.

What scale is the Japanese hiking map?

The national base map is 1:25 000. One centimetre on paper is 250 metres on the ground. Contours are every 10 metres, with a thicker index contour every 50 metres.

How are heights measured on Japanese maps?

In metres above the mean sea level of Tokyo Bay, the national height datum. Mount Fuji's 3 776 metres is measured that way.

How are hiking trails shown on the GSI map?

As thin dark dashed lines. The map does not distinguish an easy path from an exposed route with chains and ladders, and it does not show walking times. Check a current route description before relying on a dashed line in steep terrain.

How do I find mountain huts on the GSI map?

There is no hut symbol. Huts are drawn as small buildings with their name. Look for labels ending in 山荘, 小屋 or ヒュッテ. 避難小屋 means an unstaffed emergency shelter, not a staffed hut.

Can I use the GSI map offline?

The GSI website needs a connection. For the mountains you need paper sheets or an app that downloads the tiles first. Traverse lets you save a region of the GSI map, with your route and terrain layers, for use without signal.

Sources

• Geospatial Information Authority of Japan (GSI)
• GSI Maps, the official online map
• GSI tile list and specifications
• GSI content terms of use (Public Data License 1.0)
• GSI map symbol reference