Walk a little too far down Manhattan’s East 25th Street and you’ll find yourself standing on English soil.

No, not something created by treaty like an embassy or consulate, but rather, actual English land, brought to the Port of New York during some of the darkest days of World War II.

The small outcropping of land near East 25th Street that houses the architectural landmark Waterside Plaza, as well as a small stretch of the FDR Drive, was made out of landfill from the English city of Bristol during WWII.

As German forces fought furiously to break British resistance and conquer Europe, U.S. and Canadian merchant marine vessels steamed across the Atlantic to keep the British defenders supplied against Nazi Germany’s assault. These ships were loaded to the brim with weapons when they set out on their journey, risking U-boat and air attack with a cargo that was apt to explode. When they arrived, the supply ships delivered so much cargo, with nothing to bring back, that they needed ballast to stabilize them for the return journey.

The men and women of Bristol, many of whose homes had been utterly destroyed by the Luftwaffe’s air assault, loaded these ships with the rubble of their city. Acting as ballast, these literal chunks of England returned to the U.S., where merchant marine vessels offloaded them into the East River and picked up fresh cargo to return to Europe.

The resulting landfill created the area known as Bristol Basin, quite literally built from part of England.

In 1942, the English-Speaking Union of the United States erected a plaque commemorating Bristol’s unique contribution to New York City. Nearby, the British International School houses its River View Campus in Waterside Plaza’s Building 20. The plaque itself has moved around over the years, and now overlooks a portion of the East River with spectacular views of Queens and Brooklyn.

The Plaza itself is of architectural interest as well, with its buildings’ unusual geometries distracting from their common brick construction. At the same time, Waterside Plaza houses sitting areas, public gardens, and many interesting shops—all of them sitting atop the remnants of 1940s Bristol, England. It’s a little-known testament to the iron will of the United Kingdom, and all-important cooperation, during WWII.