It's easy to notice some strange red building just near the President's Office. Lenin was a kharismatic leader of Russian Revolution. When he died in the January of 1924, it was a huge question for allother leaders how to memorize Lenin in the best way.
It was a cold winter, so body was perfectly preserved due to the low temperatures. Many people came to Moscow to bid farewell. So till the end of the winter, body layed in the small wooden mausoleum in the Red Square. In the spring everything started melting...
We don't know why, but at that times leaders decided to create a personality cult of Lenin. They mumified the body and put it back to another wooded mausoleum at the same place. Only in 1930s these red building was build becoming the sacral place, the ziggurat of the main God of the Communost Pantheon.
Ironically, that the creator of communist Russia nowadays works as a tourist attraction in the capitalistic world.