10-Z is the code name of probably the most highly classified nuclear fallout shelter in Brno dating back to the communist era, whose purpose was to protect the city's and region's representatives.
The 10-Z nuclear fallout shelter
It had been built during the Nazi occupation as a civil defense (Luftschutz) shelter from American and Soviet bombardment of Brno.
In 1946-1948, here inside the hill atop which Špilberk Castle stands, a successful wholesale wine store flourished, Löwy and Šmíd, but the communists confiscated it from its owners just two days after having usurped power in February, 1948. The nuclear fallout shelter was completed in 1959. It could house up to 500 important municipal and regional officials for three days in a time when Czechoslovakia was under no actual threat of nuclear attack, and when the communist regime suppressed any and all expression of freedom made by its own citizens.