The concentration camp established on Polish territory was the administrative centre of a huge camp complex.
The palace of Charlemagne was not only the centre of his empire, but also a centre of culture.
Practise the English alphabet, build words from letters.
Karst formations include dolines and dripstones.
Practise the Russian alphabet, build words from letters.
The boundaries of tectonic plates can be seen on the seafloor.
A glacier is a large body of ice that forms from snow, and is in constant, slow motion.
Submarines had an important role in naval warfare as early as World War I.
Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).
As opposed to underground mines, in open-pit mines the layers covering coal are removed, coal is extracted on the surface.
These special dolmens located in present-day Netherlands were built about 5,000 years ago.
The colonising powers´ colours were wiped off the map by the nations fighting to regain their independence.
This animation demonstrates how muscles and vertebrae move the head.
The battle of the Greek-Persian War became famous for the heroic sacrifice of the Spartan soldiers.
The Rosetta Stone helped to solve the mystery of hieroglyphics.
Wind, as an external force, plays an important role in shaping coastal areas and steppes.
The dodo is an extinct species of birds that used to be native to the island of Mauritius. It has become the symbol of extinction.
The Kepler space telescope was launched by NASA to discover Earth-like planets orbiting other stars
A geisha is a traditional Japanese entertainer whose skills include performing classical music and dance.
The Vought F4U Corsair radial-engined naval fighter was one of the most prominent American aircraft of the Second World War.