The Kremlin (which means fortress) is the original Moscow, a settlement first mentioned in 1147, and founded by the prince of Kiev, the city state that ruled Russia until the 14th century.
The Kremlin is the former residence of the Czars (until Peter the Great moved the capital to St. Petersburg). It houses a number of famous cathedrals on Cathedral Square as well as government buildings.
The first building we saw was the former Communist Party Congress built by Khrushchev.
The next building is the Russian Senate, where Putin works when he is in Moscow. 
We was the 1586 Czar Cannon,
the 16th century Czar Bell, which weighs 200 tons and was too big to move.
On Cathedral Square, we saw the Cathedral of Assumption, where coronations took place (no pictures allowed inside).
The Cathedral of Annunciation was the private chapel of the Czars.
The roof of the tiny Church of the Disposition of the Virgin’s Robes is gorgeous.
The Cathedral of Michael the Archangel was where 56 members of royal family were buried (before they began to be buried in St. Petersburg). 
doors to Church of Archangel
The Kremlin gardens