The Free City of Danzig, 1920–1939 — What Traces You Can Still See Today

The “Free City of Danzig” comes up in almost every account of the city’s history, but few explain what it actually meant — and fewer still show where, walking around Gdansk today, you can actually see its traces. It was a political entity that existed only from 1920 to 1939: not Germany, not Poland, but an autonomous city-state under League of Nations supervision. Here’s exactly what it was, how it came into being, and how it ended — and, above all, which buildings, squares, and museums let you see that history with your own eyes, and how to turn them into a sensible route.

What the Free City of Danzig actually was

The Free City of Danzig (German: Freie Stadt Danzig) was a separate political entity — part of neither Germany nor Poland. It had its own constitution, approved by the League of Nations, its own anthem, a single-chamber parliament (the Volkstag) and government (the Senate), its own police force, and, from 1923, its own currency — the Danzig gulden, which replaced the devalued German mark — along with its own postage stamps. The large majority of residents spoke German, and that shaped the city’s everyday life.

At the same time, the Free City was not fully sovereign: it had no army of its own and no independent foreign policy. Oversight rested with the League of Nations, represented locally by a High Commissioner. Poland, in turn, held specific, clearly defined rights within the city: a customs union, its own postal service, its own schools, and — which turned out to be pivotal for the events of 1939 — the right to operate a military transit depot on Westerplatte. In other words, this wasn’t “simply a German city” or “simply a Polish city,” but a complicated, dual-authority compromise, designed to reconcile the German-speaking majority with the need to give the newly restored Polish state access to the sea.

The Free City also covered a much larger area than Gdansk itself — its full territory measured close to 2,000 km² and stretched from Sopot (then the separate municipality of Zoppot) to the rural areas of what is now the Żuławy region. Oliwa, today a district of Gdansk, was a separate town within the Free City’s borders until 1926, when it was administratively incorporated into Gdansk. The entire border, roughly 290 kilometres long, was marked by 740 granite boundary posts — some of them, now heavily weathered, still stand in the landscape, though they’re more a destination for history enthusiasts than a stop on a typical walking route.

How it began, and how it ended

The Treaty of Versailles, signed on 28 June 1919, provided in Article 100 for Danzig and the surrounding area to become a separate entity under League of Nations supervision — that was a treaty decision, not yet an accomplished fact. The Free City of Danzig itself was formally established later: it was proclaimed on 15 November 1920. These two dates are sometimes confused or merged into one in various accounts — it’s worth keeping them separate: 1919 was the decision, 1920 was when the state actually came into being.

For its first decade, the Free City functioned as a relatively stable, multilingual economic entity, living mainly off the port and transit trade. That changed after 28 May 1933, when the NSDAP won 38 of the 72 seats in the Volkstag elections — an absolute majority. The new Senate, dominated by the National Socialists, systematically took over one city institution after another; from October 1933, the Senate was made up entirely of NSDAP members. The de facto local leader, Albert Forster, who styled himself Gauleiter of the Free City, openly pushed for its incorporation into Germany.

The successive League of Nations High Commissioners responded to this in different ways, which is also part of the story. The Irish diplomat Seán Lester, Commissioner from 1934 to 1937, openly opposed the NSDAP-dominated Senate’s breaches of the Free City’s constitution and reported these violations to Geneva — with little effect; he was recalled from his post in February 1937. His successor, the Swiss diplomat Carl Jakob Burckhardt, held the office right up to the end, until 1 September 1939, when the Free City’s authorities declared its incorporation into the Third Reich — bringing just under nineteen years of separate statehood to a close.

Timeline — legal status and what’s left of it

Traces in the centre — a route you can walk

Several of the most important traces of the Free City stand in the city centre, within walking distance of one another. The Nowy Ratusz (New Town Hall) at Wały Jagiellońskie 1 — formerly the headquarters of a Prussian army corps command — served from 1920 to 1939 as the seat and office of the successive League of Nations High Commissioners in the Free City of Danzig. Today it houses Gdansk’s City Council; you view the building from the outside, walking along Wały Jagiellońskie toward the train station. One of the rooms inside (no. 003) is now named after Seán Lester — the High Commissioner whose clash with Danzig’s National Socialists we cover above.

A dozen or so minutes’ walk from here, on Plac Obrońców Poczty Polskiej, stands the building of the former Polish Post Office — which operated in the Free City under Polish postal rights, and was attacked on 1 September 1939. The square itself, with its monument to the defenders, and the building’s facade are open public space; the museum inside has been closed for renovation since January 2025, with reopening planned for September 2026 — check the current status at muzeumgdansk.pl before your visit.

The third stop is the Main Town Hall, the principal seat of the Museum of Gdansk, where you’ll find exhibits covering various periods of the city’s history, including the inter-war years. The museum is currently preparing a new, comprehensive department devoted to the whole history of Gdansk, so it’s worth checking on site or on the museum’s website beforehand exactly what the current exhibition covers — including whether the Danzig gulden or Free City postage stamps happen to be on display. This same route overlaps largely with the Royal Route, which we’ve covered step by step in → The Royal Route in Gdansk.

Traces beyond the centre — Westerplatte, Nowy Port, Wrzeszcz

Westerplatte is the best-known trace of the Free City — a peninsula where, under a 1924 League of Nations resolution, Poland operated a Military Transit Depot, which was attacked on 1 September 1939. The ruins of the barracks and the monument to the defenders are today part of the → Museum of the Second World War; we’ve covered how to get there and how much time to plan separately in → Westerplatte — how to get there and visiting.

On the way to Westerplatte, in the district of Nowy Port, stands a working lighthouse from 1893–1894 — older than the Free City itself, but standing within its territory for the entire period of its existence, with a viewing gallery looking out over Westerplatte and the Bay of Gdansk. The lighthouse is open to visitors seasonally, for a ticket; check its current hours and visiting rules directly on its own website before you go, as they change over the course of the year.

If you have more time, it’s worth a look at Wielki Wrzeszcz too — a quarter of townhouses and villas around today’s Kościuszki, Chrobrego, Legionów, and Hallera streets, built in exactly the 1920s and 1930s, when this part of the city was called Neu-Langfuhr. The buildings survived the war relatively intact and today form an ordinary residential district — with no museum plaques, but with architecture that dates directly from the Free City years.

Can you cover this in half a day?

The three stops in the city centre — the Nowy Ratusz, the Post Office, and the Main Town Hall — fit comfortably into 2–3 hours of walking, since at most a dozen or so minutes on foot separates them. If you add Westerplatte and Nowy Port, plan on a full day: getting there one way (by bus, bike, or the seasonal water tram from the Motława) takes about half an hour, and visiting Westerplatte itself takes another hour or more. Wrzeszcz is most conveniently folded in on the way to or from Gdańsk Główny station, since it’s just a few SKM stops from the city centre.

The most logical order: start with the Nowy Ratusz and the Post Office in the centre, have lunch in Główne Miasto, and set the afternoon aside for Westerplatte and Nowy Port — the late-afternoon light works well from the lighthouse gallery, looking out over the bay.

Where to see more, and read on

Beyond the places listed above, everyday objects from the Free City — the Danzig gulden, postage stamps, official documents — appear periodically in temporary exhibitions at the Museum of Gdansk and local historical societies. If you’re specifically interested in seeing coins or stamps, ask directly at the Main Town Hall what’s currently on display — temporary exhibitions change several times a year. The next chapter of the city’s 20th-century history — the post-war one, tied to Solidarity — is on the other side of the centre, at the former Gdansk Shipyard: we’ve written about it in → Gdańsk Shipyard and the ECS — a walk through Młode Miasto.

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Bastion Wałowa is the most convenient base for this route. The → Bastion Wałowa apartments are a few minutes’ walk from the Nowy Ratusz, the Post Office, and Główne Miasto, and of all the Mint locations, this one also puts you closest to Westerplatte and Nowy Port. Questions about the route or getting there? Message our concierge: rezerwacje@mintapartments.pl, WhatsApp +48 797 412 679.