On April 20, 1925, Colonel Percy Fawcett, his elder son Jack Fawcett and Jack’s lifelong friend, Raleigh Rimmell, departed from Cuiabá, the capital city of the Brazilian state of Mato Grosso, to find “Z” — Col. Fawcett’s name for what he believed to be an ancient city lost in the uncharted jungles of Brazil. The search for the mysterious Lost City of Z would be the great explorer’s last expedition. All three men would vanish without a trace.

The life-sized terracotta warriors of China are known throughout the world. This clay army of 8,000 including infantry, archers, generals and cavalry was discovered by archaeologists in 1974 after farmers digging a well near the Chinese city of Xian unearthed pieces of clay sculpted in human form.

Beginning in the 1950s, American and Soviet scientists embarked on a perilous race to see who could build and detonate the world’s largest bomb. The results exceeded all expectations about how big a bomb could be built. Initially, the Americans led the way, but then left the field clear for the Soviet Union to break all records.