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Three small survey marks on a Japanese map, built from the same parts and answering three different surveying questions.
Count the sides and look for the mast. A triangle with a dot at its centre is a triangulation station, which fixes a position horizontally. A square with a dot at its centre is a levelling benchmark, which fixes a height. The same outline with a short upright stroke rising from it is an electronic reference point — a permanent GNSS receiver, and the stroke is its antenna. All three are drawn at nearly the same size and all three have a central point, so the enclosing shape and that one extra stroke carry the entire distinction; if you are working from a scan or a photograph, this is the group most worth checking against the printed legend rather than trusting at a glance.
| Japanese map symbol for a triangulation station | Japanese map symbol for a levelling benchmark | Japanese map symbol for an electronic reference point | |
|---|---|---|---|
| Japanese name | 三角点 — sankakuten | 水準点 — suijunten | 電子基準点 — denshi kijunten |
| Outline | A triangle. | A square. | A survey-point outline carrying a short upright stroke. |
| What it fixes | Horizontal position, by triangulation. | Height above the levelling datum. | Both, continuously, by satellite observation rather than by sighting. |
| What is physically there | A set stone or marker at the surveyed point. | A set marker whose height is published. | A permanent instrument in a housing, tall enough to see from a distance. |
| Commonest error | Read as a benchmark when the outline is unclear. | Read as a triangulation station when the outline is unclear. | Read as either of the other two, because the antenna stroke is the first thing lost in reproduction. |
| Relationship (from Symbolwise's records) | Commonly confused with Japanese map symbol for an electronic reference point — The electronic reference point is a survey-point outline carrying an antenna stroke, not a triangulation station.; Commonly confused with Japanese map symbol for a levelling benchmark — The levelling benchmark is the same construction with a square in place of the triangle. | Commonly confused with Japanese map symbol for a triangulation station — The triangulation station is the same construction with a triangle in place of the square.; Commonly confused with Japanese map symbol for an electronic reference point — The electronic reference point adds a short upright antenna stroke to a survey-point outline. | Commonly confused with Japanese map symbol for a triangulation station — Without the antenna stroke the mark is an ordinary triangulation station.; Commonly confused with Japanese map symbol for a levelling benchmark — Without the antenna stroke the mark is an ordinary levelling benchmark. |
Map symbols used on Japanese topographic maps
Geospatial Information Authority of Japan (GSI) · retrieved 2026-08-23
Japan's national mapping agency's own published legend. Cited for the form and meaning of a symbol on Japanese topographic maps; the historical origin of individual symbols is cited separately where claimed.
A building's assembly point is a safe place to stand once you are outside. A ship's muster station is a staffed step in a procedure: you are counted against a roll, briefed, and if necessary allocated to a survival craft, which is why it has a letter or a number and appears on your cabin door card. Both are green, both show grouped figures, and both are called an assembly point in ordinary speech — and treating a muster station as somewhere merely to wait is the misunderstanding drills exist to correct.
Follow the teeth. They always point downhill. Teeth running outward and away from the crest line mean the ground was built up — an embankment carrying a road or railway above the surrounding land. Teeth running inward, towards the line, mean the ground was cut away — a cutting taking the route below it. The two marks are deliberate mirror images of each other, which makes them easy to tell apart once you know the rule and almost impossible to guess if you do not, because both read as a line with hatching. This is one of the few map conventions where knowing a single rule settles the question permanently.
Land cover on a Japanese map is drawn as one small motif repeated across an area rather than as a single symbol, and the categories come in pairs that differ by exactly one feature. Paddy against dry field is two small strokes drawn two ways. Broadleaf against needleleaf is a rounded canopy against a pointed one on the same trunk. Timber bamboo against dwarf sasa is woodland against ground cover. In every case the pair covers the whole of a category between them, so identifying one is really a matter of deciding which half of a pair you are looking at — which is why these six are worth reading together rather than one at a time.
A circle drawn around a Japanese map symbol raises its rank. The same 文 character is a primary or lower secondary school on its own and a high school inside a circle; the same crossed truncheons are a neighbourhood police box on their own and a full police station inside a circle. Once you know that, three separate identification problems collapse into one rule, and the reason the marks look so alike stops being a defect of the map and becomes the point of it. The circles around the public-administration marks work slightly differently and are the exception worth knowing: there the distinction is not plain-versus-circled but what sits inside the circle, and those three are genuinely easy to confuse at map scale.