The Blockhouse is a 1973 British survival drama film directed by Clive Rees and starring Peter Sellers, Charles Aznavour, Jeremy Kemp, Per Oscarsson, Peter Vaughan, Nicholas Jones and Leon Lissek. Based on a 1955 novel by Jean-Paul Clébert and produced by Edgar Bronfman Jr., it is about a group of forced labourers during World War II, who become trapped in an underground storehouse for years. It's noted as a rare dramatic role for Sellers.

The film premiered at the 23rd Berlin International Film Festival, where it was nominated for the Golden Bear. Despite positive reviews, it was not widely released in the United Kingdom and failed to find an audience.

On D-Day, a mixed-national group of forced labourers held by German forces take shelter from the bombardment inside a German bunker, but are then entombed when the entrances are blocked by shelling damage. By coincidence, the bunker is a storehouse, so the prisoners have enough food and wine to last them for years. However, they are trapped not for years but permanently, and the film analyses how they deal with their underground prison, with their relationships, and with death.

The book and film appear to have been inspired by a possibly true story: On 25 June 1951, Time magazine reported that two German soldiers claimed to have been trapped for six years in an underground storehouse in Babie Doły, Poland. They had survived on canned food and condensation. Four of the six years were spent in total darkness after they ran out of candles. There were originally six men, but two committed suicide and another two died of natural causes. Upon their rescue, one died of a heart attack immediately upon seeing sunlight, while the other was hospitalized.

Various other dates and locations have been given for the alleged incident, including 1947 and 1948, and Gdańsk. A 1955 short story called "Gdy zgasnienie Słońca" ("When the Sun Goes Out"), by Polish writer Zenon Skierski, was supposedly based on a diary of the survivor of the incident. Other creative works, including a poem and a stage play, had been written about the incident.

The veracity of the report is unclear, the reports made no mention of the men's names, nor of the sole survivor's ultimate fate. By the late 1950s, the story had been widely reported in Germany and was considered a hoax there. A 1958 report by Der Spiegel reads:

"Because the Polish side did not comment on the reports - as late as last week the press office of the ministry of the interior in Warsaw said "we do not know this case at all" - the producers of so-called true stories have repeated the popular episode in many different forms for years. Last December ... even a first East-German version of this old horror story appeared ... which was created by a secondary school teacher named Hans Pfeiffer from Grimma in Saxony. The Pfeiffer story could as well have been from a West-German tabloid, especially since the author tried to increase the drama by adding a twelve-year old refugee girl to his vault dwellers."

That same year, the West German film Nasser Asphalt portrays an event similar to the alleged incident as a fabrication.