Trig points

Each red triangle marks a trig pillar. Tap or click one to see its grid reference, trig ID and coordinates.

Reference circle

Zoom in close enough and a 250m circle appears around each trig — a quick visual reference for the area immediately around it.

WAB grid

The Ordnance Survey 10km grid (or the Irish Grid over Ireland). It only draws once you're zoomed in far enough to read it clearly.

UKBOTA

Toggles UK bunkers on the map. Zoom in close enough and a 1000m circle appears around each one, same as the trig reference circle.

Summits

Toggles SOTA summits on the map, shown as green triangles with olive-drab clusters when zoomed out.

Lighthouses

Toggles UK lighthouses on the map, shown as amber towers with blue clusters when zoomed out.

My location

Shows your current position on the map. Your browser will ask permission first — nothing is shared until you allow it.

Search

Search by grid square (e.g. TA32) or reference (trig ID, e.g. TP5437, or — once toggled on — a bunker, summit, or lighthouse reference/name too). A single match zooms straight to it and opens its details.

Type a full 6, 8 or 10-figure grid reference (e.g. HU123467, HU12346789, or the Irish single-letter form) and a red cross drops on that exact point and the map zooms in on it.

You can also type a latitude/longitude pair (e.g. 59.89226, -1.31283 — the comma is optional, and any amount of spacing works) to do the same thing.

Or go the other way: double-tap (or double-click) anywhere on the map to drop the same cross and popup, worked out for that exact spot.

Numbered clusters

A numbered circle stands in for several nearby trigs. Click it, or zoom in, to break it apart into individual points.