The work of smiths – one of the first professions in history – became even more important in the Middle Ages.
Medieval Venice owed its wealth to its flourishing maritime trade.
The Olympic Games, held in the town every 4th year after 776 B.C. made it one of the centers of ancient Greece.
The suspension bridge that stretches above the strait between San Francisco Bay and the Pacific Ocean was opened in 1937.
The city with advanced culture was the first settlement in history to have a citadel.
Archimedes was one of the most brilliant Greek scholars of ancient times, who made his mark with military inventions as well.
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 traveled great distances on the seas and rivers.
Hydrogen atoms within hydrogen molecules are held together by a covalent bond.
Fatty acid molecules consist of a polar head and a non-polar tail, therefore they are suitable for removing fat stains.
The device designed to carry out executions more humanely than before was named after a French doctor.
Jamestown, founded in 1607, was the first permanent English settlement on the east coast of North America.
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.
Ancient Roman conquerors had effective siege engines developed for attacking fortifications.
As the Roman Empire expanded, military camps were established on the newly conquered territories.
Uranus is the 7th planet from the Sun, a gas giant.
Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).
The palace of the Frankish Emperor, Charlemagne, was not only the center of the Empire, but also a center of culture
Saturn is the second largest planet in the Solar System, easily recognisable by its rings.