The Treaty of Versailles ran to hundreds of articles, and two of them concerned narrow slices of German dockland. Article 363 required Germany to lease areas in the ports of Hamburg and Stettin to Czechoslovakia for ninety-nine years, under free-zone rules that let goods pass straight through. Article 364 established a commission — German, Czechoslovak and British delegates — to fix the boundaries, the equipment, the conditions of operation and the rent, with revision possible every ten years. The reasoning was purely geographic. Czechoslovakia was newly independent and entirely inland, and the Vltava flowing into the Elbe was its only navigable road to open water. Germany announced in advance that it would accept whatever the commission decided; the lease was then formalised as a German–Czechoslovak agreement, signed in Prague on 16 February 1929.

The ground itself is unremarkable, which is part of the pleasure of it. The Moldauhafen was excavated in 1887 as one more rectangle of water in a port already full of them, and it lay inside the Hamburg free port, a customs-free enclave. Beside it, the Saalehafen forms part of the same Czech holding. A third site, the Peutehafen — about 13,500 square metres on the narrow peninsula between the Peutekanal and the dock — was not leased at all but bought outright by Czechoslovakia in 1929, and sits outside the free port. In the paperwork, the leased ground carried a name only a treaty could have produced: the Czecho-Slovak rental zone for inland navigation in the free port of Hamburg.

For a few decades it did exactly what it had been designed to do. In 1937 alone, 2,010 inland vessels arrived in Hamburg from Czechoslovakia with a combined carrying capacity of more than 1.5 million tonnes. Out went sugar and coal, grain and timber, glassware, ironware, cellulose and malt — a Central European economy reaching the ocean down a corridor of river and treaty. In the 1950s a towed barge was converted into living quarters and moored at the dock for the crews of Czechoslovak tugs and lighters, so that men slept on the water in a foreign country's harbour while working a stretch of quay their government held by right. Czechoslovak Elbe Shipping used the site until 2002. When the company became insolvent, the traffic largely stopped.

Versailles lapsed after the Second World War; the lease did not. Stripped of its treaty foundation, it simply became a private contract between the Free and Hanseatic City of Hamburg, as landowner, and its tenant — an unglamorous afterlife for a clause drafted at the Paris peace conference. In 1993 the Czech Republic assumed Czechoslovakia's rights and the arrangement carried on unchanged. The parallel provision for Stettin, now Szczecin in Poland, is long dead. Hamburg, for its part, would like the ground back. The city's bid for the 2024 Summer Olympics would have blocked access to the Moldauhafen entirely, and Hamburg has offered replacement land more than once — though the bid itself died when the city's voters rejected it in a referendum on 29 November 2015.

What replaces the dock is already drawn. The Moldauhafen and the ground around it are to become part of Grasbrook, a new Hamburg district mixing housing and workplaces, and a U4 underground station is planned to span the basin north to south. Hamburgers were invited to name it in an online vote, choosing between Grasbrook, Prager Ufer and Moldauhafen. Moldauhafen won, so the treaty's ghost will outlast the water it named. Prague, meanwhile, has never wanted to leave. Hamburg and the Czech Republic have spent years negotiating a swap that would give Czech firms an area of roughly equal size in the seagoing part of the port beyond 2028 — a guarantee written into a peace treaty, renegotiated as an ordinary piece of property business.