The suspension bridge that stretches above the strait between San Francisco Bay and the Pacific Ocean was opened in 1937.
The Olympic Games, held in the town every 4th year after 776 BC made it one of the centres of ancient Greece.
Tower cranes are machines used for lifting loads weighing up to several tonnes.
Farming techniques evolved with the development of human civilisation in the Middle Ages and the Modern Age.
The work of smiths – one of the first professions in history – became even more important in the Middle Ages.
Ancient Roman conquerors had effective siege engines developed for attacking fortifications.
Medieval Venice owed its wealth to its flourishing maritime trade.
The cannon was an important type of firearms at the beginning of modern history, widespread both on land and water.
These excellent shipbuilders and sailors travelled great distances on the seas and rivers.
A wide variety of torture devices were in use in medieval dungeons.
Typical working-class districts with unhealthy living conditions were built at the time of the Industrial Revolution.
Jamestown, founded in 1607, was the first permanent English settlement on the east coast of North America.
The largest type of Arab sailboat, most commonly used as trading vessels in the Persian Gulf.
As the Roman Empire expanded, military camps were established on the newly conquered territories.
A differential allows the driven wheels of a car to rotate at different speeds when the car is turning.
Hero of Alexandria is the inventor of the first steam engine, although he regarded it as an entertaining toy.
Highly committed Japanese soldiers fought primarily at the Asian and Pacific theatres of the Second World War.
The palace of Charlemagne was not only the centre of his empire, but also a centre of culture.
The concentration camp established on Polish territory was the administrative centre of a huge camp complex.
The main protagonists of World War II were tanks.