Open Historia

Cities and Structures

Cities on the map and the bases, ports and landmarks that get built during a campaign.

Two kinds of thing are drawn on top of the political map: cities, which come with the world, and structures, which get built during a campaign.

Cities

Cities come from the scenario. Modern Day's hand-drawn map carries its own list of about 2,500 cities, with their 2014 populations. A scenario on the stock world map uses a stock set of roughly seventy thousand; a custom scenario can ship its own, or import from the same database. A scenario with no cities shows none.

They appear from about zoom 3.4 and get denser as you zoom in. Click one for its name, population, whether it is a capital, and its tier.

Cities change

The world can rename a city and change its population, and it does both for real reasons:

Renaming happens when a city is renamed after a leader or an ideology, when a capital is re-designated, or when a conqueror gives a captured city their own name. It works on any city on the map, including ones that shipped with the world rather than being authored by a scenario.

Population moves when something plausibly moves it — a siege, a famine, an epidemic, a bombing or an evacuation shrinking a city; an industrial boom, a resettlement programme or a refugee influx growing one. The world always writes the new total, not the change.

That means a long campaign leaves a visible demographic trace on the map, which is one of the quieter pleasures of playing one.

Structures

Structures are markers placed during play: military bases, ports, embassies, airfields, research facilities, landmarks — the kind is free-form, so the world names whatever it needs.

Each has a name, a kind, an owner, a position, a status — planned, under construction or active — and optionally a note and a founding date. The game places a new structure by the place its event names and keeps it off other markers.

Structures never move borders

This is the rule worth knowing. A structure's owner is whoever runs the facility, not who owns the ground it stands on.

An American airbase in Germany does not make that region American. An embassy is not a piece of the sending country. Building a port in an allied country annexes nothing.

If you want the ground, that is a territorial change, and it has to happen as one.

Building and losing them

Structures appear when an event founds or constructs one, and disappear when one is destroyed. Building something with the same name as an existing structure replaces it rather than stacking a second one on the same spot.

You get structures by ordering them — "begin construction of a naval base at Gdynia" — and by the world building its own. Watching foreign bases appear near your borders is a genuinely useful early-warning system.

On beta, what an event builds is put on the map. After each skip a check — Put new structures on the map in Settings → AI — places the bases, shipyards, data centres and ground stations the events said were built; a structure it could not place says where it was sent instead. One credited to a country with no land goes to whoever holds the ground. Structures are also drawn half again as large.

Placing them yourself

The cheats panel has map-feature tools: edit an existing city or structure, add a new one, or clear out ones that have accumulated and stopped mattering.

Adding your first custom city to a scenario flips it into custom-cities mode, after which the scenario carries its own city list rather than the stock one.

For authoring a whole world's cities, use the map editor, which can import from the full city database or place them by hand.

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Open Historia is under active development on two channels, and this wiki is written by hand — a page can fall behind a release. Last checked against the game on 2026-09-24 · main e62a1c55 · beta 2f48a6c2. If something here does not match what you see in the game, trust the game and say so on Discord.