Pollution is the detrimental effect of human activity on the natural environment.
The church of the "Holy Wisdom," built in the Byzantine Empire, had been one of the largest religious buildings until 1935, when it was converted into a museum.
The most famous and most magnificent amphitheater of Rome was built in the 1st century.
This animation introduces the most important organ systems of the human body.
Large carnivores, perhaps the best known of dinosaurs.
This animation demonstrates the type of engine most commonly used in cars.
This animation demonstrates how the Earth and the Moon were formed.
The desalination process produces drinking water from seawater.
The ear converts the vibrations of air into electric signals which are then processed by the brain.
The round tower of the largest fort in the Arabian Peninsula had an ingenious defense system.
This animation presents the formulas to calculate the perimeter and area of shapes as well as the surface area and volume of solids.
This animation demonstrates different types of volcanic eruptions.
The world's most famous citadel, the Acropolis of Athens was built in the 5th century B.C., during the Age of Pericles.
Visit the workshop of the Renaissance polymath and his most influential inventions and works of art.
This animation presents some interesting facts in physical geography.
The Voyager space probes were the first man-made objects to leave the Solar System. They gather data about outer space and carry information about humanity.
The name of this magnificent palace complex originates in Arabic and means 'the red one'.
The main sources of water pollution are industry, agriculture and urban areas.
A metropolis is a large city with a population of over 1 million people.
This scene presents the location, anatomy and functioning of the central organ of the human circulatory system.