This beautiful place, nestled back in the trees of a quiet northern forest near Smolensk, Russia, is the site of something truly terrible, and one that, while possibly not as famous as many other massacres and tragedies of the World War II era, the world can’t stop thinking about.

Today, April 9, is an important date in World War II history. Seventy-eight years ago today, on April 9, 1940, the “Sitzkrieg” or “Phony War” came to an end with the German invasion of Norway, and that’s what this date is usually familiar for. However, at the same time, unbeknownst to the Western allies or almost everyone else, a terrible massacre was occurring here and at several other sites in Russia and eastern Poland. Beginning in the first week of April 1940 and continuing into the following month, the Soviet secret police, the NKVD, murdered about 22,000 people, most of them members of the Polish military, on the orders of Soviet dictator Joseph Stalin and his chief cronies. The purpose of the massacre was to wipe out the educated class of Polish men, thus making Poland easier for a Communist state to control if and when one should be established after World War II was over. Although this was not the only place where the killings occurred, this site and particularly the mass graves where the victims were buried in the Katyn Forest has given the incident its name, the Katyn Massacre.

Katyn was about many things, but at its heart was anti-intellectualism. Stalin was not himself an ignorant man, but he hated and distrusted intellectuals or learned people of any kind. He understood that a society without professors, lawyers, librarians, historians or other thinkers was easy prey for his totalitarian domination. The German invasion of Poland in 1939, and particularly the secret protocols of the treaty Stalin signed with Hitler that gave him (Stalin) half of Poland, dropped the opportunity to liquidate Poland’s learned classes right in his lap. Pre-war Poland had a law that all university graduates had to serve in the military. Capturing thousands of Polish officers, therefore, meant that he had Poland’s most educated and capable people already cooling their heels in POW camps. In early 1940, Stalin sent squads of NKVD executioners to lower Poland’s collective IQ. Few acts of anti-intellectualism in history have been so brazen or so monstrous.

The 2007 film Katyn, directed by Andrzej Wajda, about the massacre, was nominated for an Academy Award for Best Foreign Language Film. It is a raw and gripping film.

Reading about the Katyn killings is horrifying. Many were done in the basement of a nearby NKVD prison, whose walls were painted blood-red and where giant fans were kept whirring all night to drown out the sounds of constant gunshots. In many cases the executioners used German-made weapons and ammunition, just in case the bodies were found and the whole thing could be blamed on the Nazis–which in fact is exactly what Stalin tried to do when news of the massacre came to light in 1943. Even Franklin Roosevelt and Winston Churchill, who were then Stalin’s allies, refused to call him out on it despite being presented with proof that the Soviets, not the Nazis, had done it. The government of the USSR did not acknowledge responsibility for the crime until 1990, just before the collapse.

The massacre happened long ago, but Katyn has continued to reverberate through the subsequent decades. A film called Katyn, made by Polish director Andrzej Wajda–whose father perished in the massacre–emphasized the emotional wreckage that continued to haunt the victims’ families for years after the war. In 2010, the terrible plane crash that wiped out many high officials of the Polish government occurred as the plane was carrying them to a commemoration of the massacre. We must remember these events. In a world where anti-intellectualism seems to be back on the rise, we can’t afford to forget the terrible things it leads to.

The header image is from a photosphere accessible on Google Earth.