Radzyń Chełmiński Castle is a Brick Gothic monastery-castle completed in 1330 as the seat of the Teutonic Knights' Commandry.

It lies near Castle Lake (Polish: Jezioro Zamkowe) to the north of the town of Radzyń Chełmiński.

[2] In 1251, in the wake of the Prussian Uprising, the original wooden fort was remade in brick in 1270–1285, destroyed, then rebuilt in its current form in 1310–1330.

[2] In September 1410, after the Battle of Grunwald, it was captured by Polish forces, but soon returned to the Knights with the first Peace of Thorn (1411).

The southern buildings, eastern extension, moat, and nearby small lake no longer exist.