The Kremlin is a historic fortress and complex on the Moscow River that is sometimes referred to as the world's eighth wonder. It is the main symbolic structure in Russia and can be traced to the foundation of Moscow (1147). Originally built from wood, the fortress was destroyed in 1238 by Mongols. The second version of the Kremlin - also wooden - was again destroyed, this time by the great fire of Moscow (1365). The third version of the Kremlin - this one built from stone - did not prevent the Mongols from taking and burning the city and Kremlin again in 1382.
As Moscow became the dominant city in Russia, its grand dukes decided to upgrade the castle. In 1485 a group of Italian architects started work. They came up with the idea of the Kremlin as we know it today. Instead of tearing down the old walls, they built on top of them. As a result the walls have become exceptionally thick and the castle resembles the original one. However, the strength of the Kremlin quickly became almost inconsequential as the Russian state expanded its power. The defensive role became replaced by a symbolic one.
The Kremlin has been the residence of Russian rulers, tsars, emperors, soviet leaders, and presidents. Today the citadel is the location of ceremonies, the official residence of the Russian president, and a museum with the four palaces, four cathedrals, and twenty towers that have survived the centuries.