3. A Smallpox Outbreak (and Massive Containment Program)

A top-secret lab was established in 1948 on an island in the Aral Sea which managed to develop smallpox weapons and conducted an open-air test (one wonders why?) in 1971. To their amazement it actually worked resulting in widespread illness. Hundreds had to be quarantined and about fifty thousand were vaccinated within a fortnight. The incident became known to public in 2002. Government never acknowledged this incident and all the documentation has been kept a secret.

2. Secret Cities

Imagine living in a city which is not marked on map and where no buses stop. The city doesn’t show up anywhere on the grid. To many people in Russia this is not something hard to imagine, they are in fact living in such cities. These cities have been kept a secret due to the fact that they house certain secret activities such as nuclear fuel processing plant. The town of Ozyorsk was unknown even in Russia until 1986.There are now forty two such known cities now and fifteen more are suspected to exist.

1. The Katyn Massacre

A massacre that claimed the lives of 22,000 captured Polish prisoners and had them buried into mass graves in 1940, blamed on Nazis, and admitted in 1990; thats the Katyn massacre. The cover up was made possible by the helpful hand of US and Britain. “His Majesty’s Government have no wish to attribute blame for these events to anyone except the common enemy,” wrote Churchill. This incident takes the number one spot because of the fact that this cover up was made possible by the combined efforts!