A replica of a Nazi concentration camp opened in central Prague on Sunday to mark the 70th anniversary of the killing of top Nazi official Reinhard Heydrich by Czech paratroopers trained in Britain. On May 27, 1942, a paratrooper threw a bomb at Heydrich\'s car in Prague, sparking an unprecedented retaliatory sweep that saw 15,000 people detained, killed or taken to concentration camps. Heydrich, Nazi Germany\'s highest official in the Bohemia and Moravia protectorate on the territory of today\'s Czech Republic, died of his wounds on June 4, 1942. He was one of the main architects of the Holocaust. To retaliate, the Nazis flattened two Czech villages the same month, before killing 254 helpers and family members of the paratroopers in a nine-hour execution at the Mauthausen concentration camp in Austria in October 1942. Seven paratroopers were killed or killed themselves on June 18, 1942 in a church near the square where the replica camp is situated, after fighting a Nazi commando for hours. Defence Minister Alexandr Vondra said the Heydrich killing was \"the best military action of this nation in the 20th century.\" \"The coordination of the paratroopers... with dozens of anti-Nazi fighters here, that required a perfect plan and a heart, not only brains,\" Vondra told AFP. \"It was a very important act, which brought further suffering but also demonstrated that Czechs are able to take action against terror and Nazi totality,\" he added. Visitors to the exhibition, organised by the Post Bellum non-governmental association, enter the camp through a gate adorned with the Nazi eagle and swastika above an \"Arbeit macht frei\" (Work will set you free) sign. Then they march along a narrow corridor, under barbed wires and low-hanging lamps, before entering three dark-grey wooden barracks where the story of people involved in the Heydrich killing is told on panels. Besides the paratroopers and German officers, the panels focus on ordinary Czechs who helped the paratroopers and often paid with their lives.