Abstract: The invention relates to a freight container (1) having sides (10, 20) oriented perpendicularly to each other and defining an internal cargo space, and having a rectangular access opening which allows access to said cargo space, said access opening being surrounded by straight sections of a groove (43), said sections being oriented perpendicularly to each other, said groove (43) extending in a plane which is substantially parallel with the access opening, said freight container (1) having separate groove connection devices (50) with a groove (51) which has a cross-sectional shape corresponding to the groove (43), and which forms a continuously extending smooth transition between two adjoining sections of the groove (43).